Let me explain. I have been to countless dentists, periodontists, and orthodontists. I have also had countless encounters, good/bad experiences (not all of them are good/experience) in dentistry school; the textbook did not teach the dentist what product (e.g. toothbrush is the best); therefore, usually when u ask a dentist this question they could not give you a definite answer, they could only provide you with a reference, on what to be a good toothbrush. Typically, they will recommend soft toothbrushes, the most common reply they give you. For more than 15 years, I have learned that there are a lot of gimmicks in the market when it comes to oral care, so a lot of times, dentists have to experience the problems personally to get an in-depth understanding of the different complex problems of other patients. However, this is usually not the case. Most of the time, their oral care and health are always in tip-top condition. Therefore, they could only advise you based on their experience and what they learned in dentistry school. (school did not teach which toothbrush and brand is the best)
Toothbrush I've tried
- Electronic toothbrushes such as oral-b (the most common brand in the market)
 
- Sonicare type - Micro vibration
 
- Manual toothbrush - Diff. Formation of the toothbrush, shape, size (i.e. wide, narrow, oval, diamond), and bristle, including bristle shape (i.e. rounded tapered, density, softness, and length of the brush is considered)
 
NOTE: This doesn't mean softness is good, although softness is the most basic criterion for a toothbrush (i.e. if super duper soft or less support when slight pressure is applied, the bristle may bend and not hit the gum line). However, soft toothbrushes also include how to bristle is binding together and the shape of the bristle (e.g. tapered or rounded etc.). For example, high-density (the market is selling high-density bristle) soft toothbrushes are usually less efficient because the bristle closely binds, making it harder to reach small/tiny gum areas or between the teeth. However, it is efficient on the surface of the teeth (usually surface is not the most important area. It requires less skill/technique to brush, that's some pros and cons). Not only it's hard to get in the tiny areas because of the density of the toothbrush it creates more pressure, and it hurts the gum more easily.
Of course, brushing techniques are crucial. For example, short strokes, circular motion, angling, direction etc. determine whether you brush it correctly. I always recommend users try brushing with a newly bought toothbrush without toothpaste to see how you gonna angle or hit the spot perfectly because every tooth is different, and every toothbrush uses differently; once you get the hang of it, you put the toothpaste on.
ELECTRIC TOOTHBRUSH problems: (GIMMICK)
1.) Oscillating motion (e.g. oral b) - although in recent years, they upgraded their oscillating motion into an even shorter stroke (compared to older series (e.g. pro series) in which the oscillating motion is bigger/vigorous as compared, the upgraded series is more gentle (e.g. the IO series).
Problems:
a.) Users tend to find their way to enter hard-to-reach areas. While doing that, it lengthens the duration of the brush oscillating at the particular area, which may increase the risk of receding also if the user does not focus on hard-to-reach areas (because the bristle is too dense, thick and short for some users is harder to enter) can lead to plaque/biofilm forming. Therefore, it's still very abrasive similar to the Pro series
Better and more gentle option, HOWEVER:
2.) Vibrating motion (e.g. Philip Sonicare) - the vibration works well when the pressure is gentle (don't believe it? Test it on ur finger and see how the bristle moves) like a light touch. However, when you apply some pressure (the sensor light is still green pressure within a healthy range), you will notice the bristle no longer vibrates (e.g. motor is still running, but the bristles are not moving). In addition, the head replacement is super expensive and not worth it at all, and it can wear off very fast and become ineffective.
Important of electronic toothbrush: you will notice the bristle are thicker and people with receding issues. Gum pockets in between the teeth are more difficult to enter.
Manual toothbrush (recommended):
A manual toothbrush is better in many years of trial and error. However, do note wide heads (e.g. Colgate comfort brush, Systema, darlie etc.) are less efficient at brushing the front part (behind) the teeth (you can try it, and you will understand), so most of the time, oval or diamond shape is better, take into consideration the formation 4 or 5 rows of bristle and the formation of the bristle is important to take into consideration. (FLAT HEAD is the wost do not purchase).
CURAPROX (gimmick) - selling in a lot of dental clinics: Britstle is thick and flat and could not enter the gaps or gum pockets. However, the quality of the bristle is really soft and quality, but it is not efficient in cleaning tiny areas that are prone to bacterial accumulation. (I personally tried, and it is a gimmick)
Reference (review):
Conclusion:
Therefore, after trial and error electronic toothbrush is really a gimmick. If your teeth are aligned and healthy (no gum issues or receding issues), then most toothbrushes do the job, even the most basic series. However, this is not the case for most of us.
Dentist recommendation/review on social media:
Like I've mentioned in the earlier post, in dentistry school, they are not taught which toothbrush is the best; therefore, the recommendation they provide recommending or reviewing certain products are solely based on personal opinion with the basic principle of a toothbrush taught in school no difference to a non-dentist user giving a review just that they are giving recommendations under the name of the dentist.
(just like using the name of feng shui master talking about economics and investment LOL)
Benefits of manual toothbrush:
1.) You can take more control regulating the speed, angle, and positioning at your own pace (less abrasion)
2.) You can choose different formations of the bristle that suit you best (e.g. bristle formation four-row, five rows, bristle binding, head shapes)
3.) Once bristle fray (even micro fray), throw away (do not have to follow strictly on the 3-month usage. It's not accurate - as long you are brushing right short stroke, angling, circular motion etc.)
4.) Most manual toothbrushes are softer and thinner (0.01 to 0.02mm). (Downside is that it is easier to fray, but the advantage is that it is easier to brush)
5.) There is different bristle material as well.
IMPORTANT: do not use ur hand to touch to feel the bristle when purchasing most 
accurate is to try it physically.
6.) Downside - you need to have a lot of patience and commitment
7.) Recommend compact (small head) is the best to reach most hard-to-reach areas (it's easier to find it in a manual toothbrush)
2 min brushing time is just a guideline, not a solution:
I used to follow strictly the 2 mins brushing time. It is utterly nonsense to me that the duration of brushing time depends on the formation of the teeth. If some people have crooked teeth, hard-to-reach areas, or long teeth due to receding (i.e., need to separate upper/bottom area from brushing), a longer duration is inevitable. Therefore, I feel duration aside, as long you do not overly brush (you do not need vigorous brushing to dislodge particles or bacteria) and use the correct technique. It is totally fine.
Conclusion: Therefore, be it electronic or not (even if you are using Sonicare micro-vibrations), you will still need a good brushing technique. Although you require less technique for oscillating electric toothbrushes, many limitations exist (e.g. bacterial-prone areas are harder to reach - it is mended for people with healthy gum and teeth). So manual toothbrush is still an ideal choice after so many decades.