I'm going to join the exodus, though for a different reason. Switched to Orbstack and ever since Backblaze refuses to back up saying "disk full" as Orbstack uses a 8TB sparse disk image. You can exclude it, but if they won't (very easily) fix a known issue by measuring file sizes properly I don't feel confident about the product.
I've also been bitten by the Backblaze/Orbstack combo, and was one of the early communicators with the OrbStack team about it.
While I agree Backblaze is overdue to exclude the sparse image, in fairness to them, no other online backup solution (other than Time Machine itself) handled it correctly either, at the time I was investigating this last year.
(I'm not even sure Apple itself handles it correctly in all cases. I had to migrate to a new macbook recently, and Migration Assistant hung while transferring my files. I deleted the sparse image, tried again, and then it worked. Possibly a coincidence, I admit, but Migration Assistant reliably disappoints me every few years.)
