I backup to Backblaze b2. I encrypt myself using rclone. Costing me $1-2/mo for about 100Gb that I'm currently using.
API key I use for automated backups is pretty much limited to write only and files are set to hidden when deleted, so not much risk, just an annoyance, if the key were stolen and they defaced my backups.
Once a year I might go delete some history to reduce my usage.
I lean towards scripts to automate setting up a system, so I don't do full system backups. Downloaded video I also mostly skip using mirrored storage. In the event of a real disaster, its an acceptable loss.