I try to automate it. I do not want to think about it or copy per hand.
I use Cryptomator for personal files I may need access to while I am not at home. You can use every cloud storage as long as the encryption is good. Just save the password handwritten somewhere, good encryption sucks if you forget the password. Thats the reason I do not use gpg keys for encrypting my files. You loose the key and have no access. You need to keep backups of your Cryptomator disk in cause of deletion or corruption. Just copy it after closing the disk to another storage location.
On iOS you can use touchid to unlock it. Works good. On macOS or linux you need to type in the password.
I only us it on 1 device at a time. Do not know what happens while writting to it with multiple devices at the same time.
For backups I can not help you. To many solutions. Just zipped up folders with password protection works well on all platforms. But only if you can choose AES as encryption. Native zip encryption already unsafe. Hope that helps.