Well, here’s the official “community maintained” docker repo:
https://github.com/nextcloud/docker
https://hub.docker.com/_/nextcloud
There’s a section about docker compose, I have my own scripts but I believe I derived them from there at some point (my memory is a bit fuzzy). I use the fpm-alpine image, if it matters.
I had heard they had rewritten it in go and got a lot more performant, not sure what else they have done. I don’t care much about the politics as long as it’s still open source (is it?).
That said, I’m a happy nextcloud user and I don’t see a reason to switch (after moving both data and db onto SSDs it’s much faster, so maybe php wasn’t the bottleneck).