As a retired CPA, I agree that it can work out better to file separately, which you can still do if you file before 5/17/21.
The long list of down-sides is often not applicable, although the dependent care credit is often lost (and any pretax dependent care would be added to income). Getting your full stimulus payment could more than cover that, especially if the lower income spouse includes the children (increasing the stimulus payment).
If the lower income spouse also received unemployment, there's a new exemption for up to $10,200 - with an income limit they may qualify for on a separate return.
The point about community property states is a good one, though. MFS generally doesn't work in those states.
