I have been upgrading my then owncloud setup now nextcloud setup for the last 10 years or so almost without issue - most issues I had where back when it was still owncloud. I think I did a wipe back then once. Nowadays even if something goes wrong I know what i can do. For instance i upgraded PHP too soon once and had to manually patch it.

Anecdotal evidence tho. Results vary. I like nextcloud because worst case all a wipe would cost me is a re-upload of my local folders over a couple of hours.