I had backblaze, and it’s really a bummer they don’t support linux. The closest one I’ve found is Icedrive, but it costs a bit more. I don’t mind paying a bit more though for a FOSS solution (technially not free but yeah). I probably only have 2 TB of actual important stuff but it would be nice to have more for future.
Cloud backups, AWS, because they’ve feed me piles of credits (less so lately though) so it’s practically free.
I back very little up to the cloud though as it’s so expensive. Basically just the storage of my local Git server which has all the configs, app and microservices I’ve built for my home automations and lab. Syncs straight from my NAS where the Git server is hosted.