it demands that I log in, to view the post??

This is the first time I heard of Sublinks, and honestly after a quick look through here in Lemmy I get the impression that main devs of Lemmy and Sublinks can work together to improve what it is currently the best option (Lemmy).

I honestly think it is way too early to have a Lemmy "replacement" even if it is all running in the Fediverse, I just think it is a split of efforts, granted, I don't know all the background that runs behind and it seems like Sublinks dev does it like a hobby too.

Regarding moving communities to Sublinks, yeah, it is up to instance maintainers, but that is a no for me, heck, I already had to recreate my stuff from the dead FMHY account I had (there was no account migration at the time), it seems like adding more decentralization to me, and we already had that with multiple repeated communities ¯\_(ツ)_/¯

Finally, don't get me wrong, options and alternatives are always welcome in my book, but as I said before, it feels like way too early for me.