@busted 

can someone from Intuit at least be useful and provide a path to purchase QB 2021 while it is still supported? So far the only solution is use QB Online OR pay an huge annual fee

I would say you are very blessed if you can find a new license for QBD 2021 for Mac or even a reused one at this time. I have been taking that search since last year for my clients. If you don't mind using the trial version of QB Desktop Windows on Parallels, you can use it for good.