i've gotten back into fighting games more the past couple years partially for the reason of losing interest in FPS in general.
the thing i really enjoy about fighting games is that at advanced levels, it becomes more of a mind game. something about trying to out-smart someone through mind games is very fun and rewarding. it also is fun when someone outsmarts you with mind games, and you have to figure out a way to then in turn outsmart them.
it is also very different than FPS games because it is solely 100% on you and nothing else. has nothing to do with where you spawn, who is on your team, what weapon you have vs your opponent, level control, etc. you are 100% in control of the outcome, and if you lose, it is flat out because the opponent is better than you.
and i definitely have less time to play games as i've gotten older. i turn 30 this year. i also like how i can get on a fighter, play 5 quick matches, and get off 10 minutes later.