So basically it seems the best available self hosted & open source option is “outline”, but since there’s a hosted SAAS version from the devs, there’s no info on how to self host it. https://janejeon.dev/running-outline-wiki-on-heroku/
I cannot recommend that regular folk try and get heroku to run an app like this. So that leaves something like confluence to be their knowledge managment app.
The situation sucks. But it’s a wake up call to take open source more seriously and that easy of installation /setup will determine how many “normies” adopt these tools.
Pragmatically, this does potentially mean that European companies could leverage our regional privacy rights to become a data equivalent of Swiss banks.