I generally like to play games on the system I originally played them on. Port or no port.
For Final Fight, I originally played the arcade, but played the SNES port a lot as well.
I own a copy of the SNES version largely for the nostalgia, but also Capcom Classics for PS2, because it retains the co-op mode from the arcade that the SNES version lost.
Regarding “retro” games, I can enjoy the heck out of Streets of Rage 4 without it impacting my appreciation of playing the original games on a Genesis.