Here's one more good protein video.
Note : he is talking more about people in general. You gotta change accordingly for your own elderly parents training regime or your own specific training regime or just the general population out there which seriously i think 1g/kg is sufficient. It's not only for muscles but also for connective tissues build and repair etc.
The thing is, some people, including my parents and in-laws last time, more like 0.3-0.4g/kg, on a few days i would not be surprised if it's 0.1g/kg.

Same goes for my FIL's sister. Durian season whole day eat mao shan wang can liao.
Basically, you over eat protein, nothing bad will happen for us with healthy liver/kidneys. |Just get fat, coz changed into glycogen and then fats when stores in liver/muscles filled up.
But some who really gun several hundreds grams of protein daily over the long run might run into health issues, but those are rarity also lah. How to take so much whey without GI issues i also dont know how, sometimes 1 scoop already a bit of flatulence (not sure if is coz of the lactose, as i dont do isolates). Just not possible to take in so much like what they mentioned 2.2-3g/kg and they are well over 100kg. What the.....do the math
ps. Actually, the first thing he mentioned, protein powder as being an incredibly "new invention", is already a bit wrong or actually very wrong depending on how you look at it. But dont mind the fella lah.

It's like saying cheese is incredibly new....hehe.