Yeah, definitely not 1-to-1 comparison as moose has a VM underneath and you can run pretty much anything

Dropbox is 2TB for the same price as your 40GB. Cool idea though.

9€/m for 40GB? Yeah no, thats a terrible suggestion!

Just get yourself a Hetzner Storage Share for 4.29€/m with nextcloud managed for you and 1TB!

https://www.hetzner.com/storage/storage-share/

That is a great offer if you're only looking for a nextcloud backup. If you also need an immich instance and some jellyfin, you need another machine.

A single purpose service is always more efficient then a more generilized one