Unfortunately, fixed matches have existed for a very long time and the smaller the league, the more of them there are. Moreover, this bad phenomenon extends to both sports and eSports.
There are known cases when even one of the team players was corrupt and agreed to fixed matches and because of this his entire team, which tried to play, lost honestly because he introduced a rather obviously theatrical game instead of playing with all the seriousness and his skill.
There are leagues fixed matches exist but bookmakers are now smarter than before where they offer services to leagues that can make them losses they don't expect. Bookmakers are services makers to casino, if a casino hire one and found out that there is a loophole the particular bookmarker of that game exploited, they do immediately stop working with such casinos and because of that reason, bookmakers has taken their job more serious not to fall victim of those leagues, they only cover areas of the leagues that are popular to manipulate.
I think for long time now, it's proper to say crypto impact on sport betting has increased over time than the traditional online sport betting. If you look at a lot of casino offering sport games partnership with sport industry, the crypto based sport bets are dominating than the ordinary sport betting. I have seen countless ads of BC games and Rollbit on X than I have seen none crypto sport betting platforms, mere looking at the ads on fields, they do more adverts than usual casino.