The fact is that today it is very popular not only Dota 2, but also counter-strike. The fact is that even for this game there are a lot of competitions around the world. I think that it is necessary to take into account not only prize pools for the players themselves, but also the ability to bet in bookmakers on the outcome of such competitions.
You are only talking about 2 of them but there are a lot of them.
MOBA (Dota2, LoL, Smite, Paladins), FPS ( Counter-Strike, Overwatch, Fortnite, Rainbow six siege) are not the only modes available on esports. Fighting games are also one of them, Tekken, Smash Bros, Mortal Kombat, Street Fighter even Dragon Ball are included in this. Evo 2019 Championship Series is the recent event and it is a great tournament, search that out. What I am saying here is that these games will increase and that means more players, more supporters and more price pools and that would really explode in the incoming years. While technology advances, this type of industry will do too.