Even if you run a hobby site it's way easier to do so with attestation. Especially if that attestation will allow you to uniquely identify the device making a request. It will end DDOS and make bans much stickier than they are today making all sorts of problematic content easier to deal with.
IMHO, there won't be a split like this if attestation or similar proposals come to pass. Simply put the number of problems that come with anonymous users dwarf whatever legitimate benefits that anonymity provides. Everyone will build sites using it because of the problems they solve. And they will ignore the segment that refuses to use them because that segment will be small and a significant chunk of them will use that anonymity to do bad things you don't want on your site.
IMHO, there won't be a split like this if attestation or similar proposals come to pass. Simply put the number of problems that come with anonymous users dwarf whatever legitimate benefits that anonymity provides. Everyone will build sites using it because of the problems they solve. And they will ignore the segment that refuses to use them because that segment will be small and a significant chunk of them will use that anonymity to do bad things you don't want on your site.