I use Nikola and it hasn’t let me down. It just works and supports all the ways I write content: markdown, asciidoc, rest, Jupiter Notebooks, html and so on. It does not have so many themes, but the default one works and it’s not hard to customise if needed. If you like to use python it’s also easy to extend. I’ve written a bit about Nikola here in case it picks your interest.

I’ve deployed it to CloudFlare pages, but GitHub pages, Gitlab pages and any other provider also work.

If you don’t need CI/CD I don’t see any reasons to choose Gitlab over gitea. But I’m still testing gitea so take my words with a grain of salt :)

At work we selfhost gitlab (paid) and I’m checking gitea for my own projects. They have a good comparison table at https://docs.gitea.com/installation/comparison

Do you also need CI/CD?