I share my experience with Grab, Bolt, Songthaew and Tuk Tuk.
I stay near to One Nimman, so experience base mainly on this Nimman area.
Grab - very accessible, cost from Day 1 98baht to mostly around 150 baht. Sat and Sun cost mostly 180baht. Monday to airport 208 baht.
Mostly good drivers except that driver to airport didn't help me in getting my luggage up to his "pickup".
Very easy to locate where to pick up and destination except 2 places names are different.
Bolt - almost every time busy, only manage to get once cost only 57 baht. Bolt has the lowest cost most of the time. Very difficult to locate where to pick up and destination as mostly in Thai. Maybe those staying in other area may have different experience.
Songthaew - most popular place you will find them. Price is fixed at 30 baht per person. Cheaper than Grab but no aircon. Happen once to a restaurant within old city, driver just ask us to alight and walk about 8 mins. We mostly talk on the return trip to alight at One Nimman. Happen once before the Sunday night market open, we want to go to Malin Plaza, driver quote as 150 baht for 2 people, I just walk away to get a Grab for 120 baht.
Tuk Tuk - only take once for experience when we are going back from Jing Jia Market, too many people waiting for Grab, I saw a Tuk Tuk, just ask price and board. 150 baht.