Nextcloud – so as to fill the space available

I ran out of disk space on my server, which mainly hosts a nextcloud instance. Surprisingly I found tons of files I deleted ages ago in
nextcloud/data/username/files_trashbin/files/

It turned out my config.php was missing an entry for trashbin_retention_obligation, which as a consequence defauls to auto. I’ve now added the following line to configure a minimum and maximum amount of days that deleted files are kept:
'trashbin_retention_obligation' => '1, 7',

BTW: I think the default behaviour at least raises a data privacy issue.