Partial migration

[tflidd]

The idea is to only migrate a part of the old setup, e.g. only the users with their passwords.

The reason might be that some are running OC for some time and they have some issues that is why they want to start "fresh". However it would be nice to keep the users with their passwords. This way you could also easily start over and skip a few major versions (if people are still on OC 8.x, it will be quite an upgrade marathon):
https://help.nextcloud.com/t/migrate-data-from-owncloud-9-1-4-to-nextcloud-12/19659

People tend to start from scratch when the upgrade procedure is too complicated. It's a lot of work and there is a certain risk to end up with a broken setup.