The service I mentioned (Hetzner, but there are others) do all the administration for you. You get a login and password into a Nextcloud instance, that's it. No administration required.
I can vouch for this. I haven't really done anything on the web interface, I use it for file sync like i used to use Dropbox, and I have clients in Windows, Linux and Android and it just works.
See here: https://www.hetzner.com/storage/storage-share