It's because of the new chipset that Apple created. If you Google for the M1 or Silicon Macs you will find a lot out about it. There's a big thread about it on the forums here. What's even more frustrating is that I still have my old MacBook but this year TurboTax stopped supporting that OS version. So I had to buy a new one. And now they don't support that. Apple released it to developers ahead of its November 2020 release, and Intuit just didn't write the software to support it.
