Nonce reuse is only expected in the sense that cryptographers have begun to accept that developers will always find a way to misuse primitives. That's why these

Nonce reuse is only expected in the sense that cryptographers have begun to accept that developers will always find a way to misuse primitives. That's why these are called "nonce misuse-resistant" ciphers. Cryptographers are not encouraging people to use this type of cipher where nonce reuse is expected. Nonce reuse should never be expected, and always be avoided. But people being people will wrongly use these constructions, so we do our best to try and limit the worst downsides of the footgun. XChaCha20-Poly1305 will not solve this problem, as you seemt o believe. It is more of a footgun, in that it too catastrophically fails under nonce reuse. Yes, it's less likely to suffer reuse in the first place due to a larger nonce size, but that ignores the context driving the creation of SIV schemes: developers who choose nonces poorly, not developers who encrypt too many messages given the likelihood of collision of a random nonce.