Most banking apps don't work on rooted Android phones. It's not the same, but I don't think it's a stretch to assume that at least these companies would force their customers to use specific software...
PGP is the solution, but the problem is, that noone likes to use it. Or it's "too complicated", because it's another password they need to remember. Or, whatever. It would literally solve nearly all of the problems we currently have with emai 🤷
No more spam, because you could filter out all unsigned or untrusted mails, no problems when your email account is hacked, because the mails are encrypted on the server. No Mailserver admin spying on your mails...
borg with an external hard drive and borgbase as a remote. I use the 2-2-1 rule (🙈), as I struggle to find a good way to do another backup and RAID does not count 😬
Using a VPN to connect to your own server for torrenting does not make sense, because that may not be 'your' IP address the traffic originates from, but it is still linked to you as you pay for the server. If you use a VPN from mullvad or something else it cannot (easliy) be tracked back to you directly. (It can, but to the outside there is just a lot of traffic comming from a single source IP, and it is not just your traffic but from a dozen other users. That's the point of using a VPN provider)
There are APC units with a really small battery that won't last OP for hours.