I use Backblaze's standard service. I look at it as cheap belt and suspenders insurance. I do onsite backups using Time Machine--along with the occasional sync to another drive.It's offsite and it's a completely independent backup mechanism. $50/year or so is essentially not worth worrying about in this context.

WRT your other comment: Yes, there's some small level of incremental security risk but there's so little that's genuinely sensitive in my storage, I'm willing to take that risk. And, yes, it's probably overkill but for the cost, there are a lot of things I spend money on that are probably unnecessary :-)