FWIW, Amazon deprecated mobi files recently and epub is the new "sideload" standard. You still have to email the file to the kindle address to be able to read them, or convert to azw3.
If you're already using Calibre, check out Calibre-Web, which essentially uses a Calibre database as the back end. The interface is so much nicer than Calibre.
Proton purchased SimpleLogin in 2022 and the creator/dev has been working there ever since. Also, you can easily create random email aliases in Vaultwarden/Bitwarden via the SimpleLogin API.
You should not trust Amazon. Multiple Ring privacy failures, including giving video footage to police without consent, Amazon employees watching Ring video footage without consent, then there's stuff like Sidewalk that uses your home network as part of a mesh network, collection of biometric days via palm readers at Whole Foods for checkout, which they then use for their Amazon One service that they sell to businesses to verify age and identity, the whole "AI powered" Just Walk Out tech in physical Amazon stores that turned out to be not AI at all but a bunch of Indian subcontractors watching video cameras, etc, etc, etc...
My solution to this problem is Jellyfin, fed by usenet-backed sonarr/radar and Tubesync to pull in YouTube channel subscriptions. Those are added to a Jellyfin library which is accessible right next to movies and tv shows.
This is all through the Jellyfin app on a 2019 Nvidia Shield Pro. It's a perfect couch-friendly setup. For just regular YouTube browsing, SmartTube can be installed on the Shield and on your phone. You can then cast to the SmartTube app on the Shield instead of to the YouTube app.
You may also want to look into Usenet instead of torrents when you're researching. Sonarr/Radarr/Readarr etc all work (in my opinion) better with Usenet.
You'll need to pay some, but the reliability is amazing, which is extremely helpful for the partner acceptance factor. I pay for two providers (newsdemon is primary and eweka is a backup) and two indexers (drunkenslug and nzbfinder), and everything has been rock solid reliable for years. Download speeds are also MUCH faster than torrents.
Combine this setup with overseerr (or jellyseerr) so your partner can find their own things to download and you might be able to get them back on board.
FWIW, Amazon deprecated mobi files recently and epub is the new "sideload" standard. You still have to email the file to the kindle address to be able to read them, or convert to azw3.
If you're already using Calibre, check out Calibre-Web, which essentially uses a Calibre database as the back end. The interface is so much nicer than Calibre.