You could actually use Backblaze for both scenarios: as a normal cloud storage where you can access stuff back n forth or for long term backups and storage.
I use Duplicacy to copy and encrypt my main folders once a week. But you can set schedules for backups as you wish. Depending on how much you’re backing up it may get a bit pricey though. I have a little under a couple terabytes backed up and pay around $6 for Backblaze. They have a client I’ve never used that might be helpful as well.
One thing I wanna look into is using Duplicacy to also back up really important documents to my proton storage.