How long has it been since AV1 was released? About eight years, and there's still no credible patent holder. The vultures are always circling around compression standards. You shouldn't take that too seriously. Even if a lawsuit is filed, there's a legal defence fund to protect against baseless claims.
Most importantly, there is no alternative. As kasabali said, the patent situation for the other codecs is a mess. Additionally, they could be hit by the same "No FRAND" problem. If someone comes forward with a patent that was used unintentionally, the situation is the same for all codecs.