lovefromisrael my near worthless n of 1 data point: I used to exclusively use low watt chargers (10w max). Now, I regularly use 30w and even 140w chargers (yes, I know it's not using all that), all providing "fast charging".
My two notes:
- My phone gets noticeable warmer on the fast chargers but not uncomfortably so. Although, I never use a charger when my phone is somewhere warm like a car dash
- I've seen zero perceptible degradation in battery life after doing this. I still easily get two full days of battery life (I charge all night, every night but end the day with about 70% most nights).
My last two phones I've kept for about 3 years each and even when I got rid of them, I didn't notice any battery life degradation. I'm sure there was some, but I never noticed.