This is the issue and it is a heuristic that people need to develop.
Your provider especially your backups provider needs to have interests that are aligned with your interests.
The non-B2 portion of Backblaze has a financial incentive to keep you from using their product and to use as little of their space as possible. This is a bad, misaligned set of incentives.
On the B2 side, all of our suspicions about the (well timed) "me too" IPO have been confirmed with each and every quarterly report showing increased debt load and the classic "losing money but making up for it on volume".
Now that money isn't free anymore it's just a matter of time.
The sad part is they don't use standard, commodity JBOD enclosures so there won't even be anything useful in the fire sale :(