Less skilled players can't distinguish better players from cheaters, and reports are usually abused and used in bad faith. Even a good-faith report really just means "I don't want to see this player for whatever reason". It's used as a signal of something in most systems but never followed outright in good games because players get a ton of useless reports.

Players in some games with custom servers run webs of trust (or rather distrust, shared banlists). They are typically abused to some degree and good players are banned across multiple servers by admins acting in bad faith or just straight up not caring. This rarely ends well.

I used to run popular servers for PvP sandbox games and big communities, and we used votebans/reports to evict good players from casual servers to anarchy ones, where they could compete, but a mod always had to approve the eviction using a pretty non-trivial process. This system was useless for catching cheaters, we got them in other ways. That's for PvP sandboxes - in e-sports grade games reports are useless for anything.

A couple of years ago the bot situation in casual Team Fortress 2 was so bad that it wasn't uncommon to land in a game where the majority of at least one of the teams was a group of cooperating bots. In those matches you have the possibility to start a kick-vote on your team mates, and those bots would immediately vote “no” if you tried to vote on any of them and because they were the majority of the team these votes always failed. And if these batch were in your enemy team all you could do was to ask the remaining, hopefully real, players on the enemy team to try to kick them. It was especially annoying when you tried to play certain game modes these bots weren't programmed to handle, they had no idea of the objective and the match would stall indefinitely, forcing you to queue for a different match. And if I remember correctly these bots were pretty much headshotting everything they got in sight. Something the server can easily detect. But VAC for example acts intentionally slow, so cheaters don't get immediate feedback.

Out of curiosity I did a quick internet search and a couple of months ago a new wave of bots has emerged. Those bots also join as majority group but never fully join the game, they simply take up slots in a team, preventing others from joining. Makes you wonder why the server isn't timing them out.

Counter-Strike has been doing this for years. It's called "Overwatch" (even before Blizzards Overwatch came out). And believe it or not it failed to reliably catch actual cheaters AND got non-cheaters in trouble (both repeatedly). A very good player is indistinguishable from a cheater with a good cheat. Sometimes people just get super lucky for a few rounds and you might get judged based on that.