It doesn’t seem to be able to do anything that a GitLab instance can’t

i didn't believe you, but yeah, just learned GitLab has a wiki editor. so yeah, this covers like 95% of the things i once used Notion for. i guess if i want to be pedantic, Notion had database relations between tables that, as the name implies, allowed it to act a bit like an relational database. (e.g. allowing columns of tables to be limited to the values of rows of other tables). admittedly a little cool but in my experience was not much more useful than a simple table