Developers have full control over servers in most cases. A viable server side anti cheat should be a thing. For every case of “client sending false data to server” we can come up with a solution to verify that to some degree. Finally, it should help a lot to rely on player generated reports and utilize replay recording on server.
But no, developers will continue to rely on 3rd party solutions (made by people who never developed a game), even infect their co-op-only games with it, and complain “uh oh we can’t handle Linux cheaters”.
Think of it as a “this game is not yet available for purchase” seal. It may also mean “we know our game is not up to standards (it wouldn’t sell well on Steam), so we chose to let idiots at epic decide if they want to pay for it, and hey it worked so that’s something”.