I’m sure you are going to get loads of feed-back on this topic with many different solutions. My backup requirements are as follows:
1 - I only backup my data. If I suffer a non recoverable issue with my MacBook or Windows machines, I would never do a full system restore, I’d rather re-install the host OS fresh and then re-add my applications (spring clean) and data.
2 - I don’t trust any single form of backup, so the 3-2-1 rule is a great idea at minimum.
3 - I’d rather restore from a local source than using BackBlaze where possible, leaving BackBlaze as a last resort panic button.
So my approach, that is a mixed MacOS and Windows solution, and one that only requires a single back blaze subscription:
Local Machine Backup
Important files are sync’d to a OneDrive (that has file versioning, not quite a backup, but something)
local USB HDD using TimeMachine
lan backup to my home server using CarbonCopy Cloner
My central home server then has the following backup
local USB HDD
Remote off-site backup using BackBlaze
KEY THING - every few months, create a file on your back-up source machines, then check for this file on your various back-up methods. Obviously not a full test, but will pick-up most issues.