do not say valorant
Starcraft
Very hard game, you must think all the time, adapt to different situations and most importantly not lose coordination, because it's hard to click 10 keys at once while managing your units and buildings
Solo esport, you don't have teammates to rely on if you're a bot like zombs, in case you become bad at the game you'll just get kicked out
Prize pools are very small, viewership is tragic, i.e. don't expect any decent salaries unless you're top-20 in the world
the ones I personally watch its CS, you almost have to start playing as a kid to have the mechanics pros have, its a very hard game mechanically and you need a lot of experience since there is no big meta changes like other games and there are veterans who have been playing tier1 competitive CS since 15-20 years