Remember, this is for an offsite backup scenario.

wasabi is cheaper than B2 unless… you store less than 1TB

Yeah, absolutely. In my case, I backup way more than 1TB.

you pay for any data you upload for 90 days minimum

Which is absolutely acceptable in a offsite backup scenario. The data there is present for a long time, and if you use a solution like Restic which has deduplication capabilities, this is not an issue.

You can only download the same amount as you store in a month without incurring egress costs.

This is false. You can only download the same amount as you store in a month without violating the terms of service. That said, I've been using Wasabi in a professional manner for a number of years now, and as long as it isn't a regular occurrence, you can always contact support and give them a heads up that you do need to have more egress in a month.

This only occurs if you have to do a full restore TWICE in a month, which I had to once due to our team not noticing that the SAS controlled had failed and was responsible for corrupting data; not the drives. Support was quick, and it was no issue. Still didn't pay for that egress.