I've finally managed to install #Nextcloud.

- It's extremely picky about apache configuration. I needed to clean house, remove a ton of wildcards, and configure very granular permissions for just the nextcloud path.
- It has a lot of moving parts and is really bad at telling you what is wrong with any of them. Webdav not working? Generic, unsearchable error. Webdav working but can't do anything because of permissions? Generic 503.

But this is a big step forward in the #GoogleDivorce.