Remember. Even if Trump wins the election he will not be president for months. There is the Lame Duck Session. And let's hope it doesn't come to that, but there are many things that can happen in a lame duck session. Not just with the outgoing president but with ongoing trials.
For example the DC case could by then have sorted out what is and isn't "an official act" (bite me Alito) and have gone to trial and convicted him.
Or a democratic president gets inspired by some ideas what an official act is and commits one and a certain would-be-president founds himself suddenly on a round-trip to Mars.
@futurebird I just went and searched my email and texts for begging requests from the 2 (so far) Dems who are urging Biden to drop out. Let 'em have it - they've got a lot of nerve asking Ds for money when they're acting like Rs. Might have said something to the effect of "wouldn't piss on you if you were on fire."