Fast charging is better when you need your phone battery fully charge quick. Regular charging speed of course take longer if you are in hurry to take your phone away.
Fast charging and Regular charging both won't damage the battery too much.
Except you charge your phone from 0% or keep charging when fully charge. This will damage the battery over time. Usually charge the battery below 40% and unplug your phone once 100%. That should fine.
Also, if you change phone every year or 2 years, don't worry about how you charge the phone, the battery works great within 2 years anyway. I keep charging my phone in 100% everyday for few hours since my Note3 til S22U, no battery dying problem.
Along with what @Tallman said, there's no perceptible difference on the life of the battery, certainly not for a couple of years or more.
One of enemies of battery life is heat, and with fast / super fast charging, there is an increased amount of heat, but not enough to do any damage.
All modern Samsung phones, will automatically stop charging when full, so you can leave the phone plugged into, or on the charger (with wireless chargers) overnight, and no damage to your battery.
