Watch last question in “Nextcloud Hub 22 live announcement and Q&A” (06.07.2021):
https://www.youtube.com/watch?v=Y0VZ7t8JGZE&t=4590s
It would be very cool to make it possible for a standard user to zip all Nextcloud stuff (files and app data) from old nextcloud and move it to another nextcloud. That would be freedom.