> I also contacted Spotify and they are absolutely sure that it's not possible to create accounts without confirming e-mails and can't do anything about it.

Yeah that's not true. We discovered someone was using my son's email address for their Spotify when he tried to register for an account. There are plenty of other accounts of this happening: https://community.spotify.com/t5/Accounts/Why-Does-Spotify-N...

It might be fixed now, but what you're saying was definitely true for a good few years.