Encrypt everything
Check drives (health etc)
Etc
1) Someone can use those to train DeepFake models and scam your family
2) There could be private photos and videos there that you aren't aware of
3) Why not?
For 3 the biggest problem with encryption is you introduce a single point of failure, if you lose access to the keys your photos are gone. On a simpler note I'm a big fan of keeping things as simple as I can. Encryption is not simple. It can be fun to work with and I don't want to ignore that but unless you want to do that for fun I don't think it's worth the complexity.
[^1]: https://cryptomator.org/
(no affiliation)
Sadly it has no gui (that I know of) but something like runtestic can help with automated incremental and encrypted backups, where you only want to keep the last n versions (and for example a weekly snapshot)
If you use Gnome, I would encourage you to use it and give feedback here [1]
