Basically because of our unawareness of probably wringed game make gambling to become a blinded fold activities and that is why we must, agree and come to the conclusion that once you set to bet on a game just expect to lose and only win if the luck is on your side, never depend so much on your skills because that can fail you.
Just to eliminate any doubt about a match being fixed it would be advisable to just focus on the big leagues, it’s not as if it’s impossible for the game to be rigged or for arrangements to be made but it’s less likely to happen than the rate at which it would happen in small leagues.
So if you bet on big leagues you could just think of it like you’re betting on a rigged free match and your analysis could work out well since nothing is being done deliberately to sabotage gamblers predictions.