The issue was the amount of illegal shit they did, that resulted in the various proceedings. The discovery for all the crimes went on too long, and as you've seen from the lawsuits that were thrown out... it's not wise to start one without rock solid evidence and a fully built case.
On the other hand the moment SCOTUS ruled that any official act of POTUS is fully legal, regardless of technical legality, he should've had Trump shot. Period.
You're presuming there would be a reasonable judge and not one already bought and paid for.