I'm not sure why one would use this "backgroundchecks" redirection link, which just appears to add ads to the top of the page. The actual site is https://justdeleteme.xyz/
I quickly checked a few of those that say "impossible" and they clearly are possible - kinda makes me think I'd be better off searching for "[service] delete account" and just doing that.
(I did notice some said "subject to applicable law" - so I guess Europe!)