I play Dota 2 myself from time to time and i also like to watch professional matches of Dota 2 since many years now and i watch almost every big tournament on twitch. I also think it is a great esports to place bets on, at least during major tournaments with a big price pool. I usually don't bet on games with low tier teams in low tier tournaments with a low price pool because there i am always afraid, that the matches may be fixed. If you only get 500$ for winning a match why would a team not accept to lose a match willingly if they get paid 600$ for example. You don't have that problems at big tournaments.