Still more or less the top gamers are not going to win every game because they are often paid by bookies to run their game and they ask for some matches to get fixed.
In what game do you mean by that word 'often'? I don't know about the other games but I'm pretty sure that in Dota 2 and CSGO the percentage of fixed match is small especially if its big tournament or atleast minor tier.
I still think that fixed match cases in esports are way less than sports, based on two games that i mentioned before.