I actually got rid of backblaze a while back because I realised I had moved machines twice and didn't bother restoring files with it. I've had backblaze for years (maybe even a decade+?!)
Code is all on GitHub, all my docs and emails are in gsuite (and don't get backed up anyway by BB). The only thing that does get backed up is a load of cruft and junk I've accumulated which is actually nice to start over on tbh.
I imagine more and more people are like this. Designers who used to have to be meticulous at backing up their source files now all work in Figma, etc etc.
The major weakness now is if GH or Gsuite had a catastrophic error (or your account gets booted off for incorrect reasons). I actually think that is the more pressing backup need than local files for many.