Informed consent requires the consenter have understanding of what is happening, know what the implications are and agree. Riot games anticheat software doesn'tpass the first two, and is largely irrelevant to the conversation because this use case is a trojan horse anyway.
Community and social graph is a finite resource. I can't just go get another one if you colonise mine.
This is exactly the same argument libertarians have against food safety and labelling regulations. I can't go get baby formula without melamine in it if every brand has it because they price dumped to bankrupt the competition and I don't have a chemistry lab to test for it.
I can't go find another bank if they all switch to requiring attestation. I can't go buy another government. I can't go find a new social graph if everyone on it is on facebook.
Operating systems and CPUs are utilities with natural monopolies, as is communication software. Treating an ecosystem, a community, and a social graph as a fungible good is a blatant lie.