A better question: who would want to play Gran Turismo 3 or 4 without pressure sensitive controllers?
Even using the original ps2 or ps3 controller with the right drivers on PCSX2 doesn't really reproduce the same smooth acceleration/brake curve of the PS2.
Playing them on a keyboard or fully digital inputs is just a miserable experience.
Right analog should be accelerate and brake.
Analog buttons were always a bad idea and should never be used.
These days you can map analog triggers to the sticks for a modern experience if you want that.