Ultimately I think the issue with this is we're trying to address a deep systematic issue through the system it's infected. Often those issues can't be solved that way and have to go around the system itself somehow. You're unlikely to be able to sue your way out of a fascist coup when it's successful for example, and similarly disadvantaged when the avenue is carrying water for a failed coup.
The thing about Biden, since you brought him up, is he's unlikely to test this in any meaningful way with regards to Trump. Could he theoretically now have the USSS detail in charge of babysitting Trump indefinitely detain him, without consequence? Maybe. But he still has at least some belief in the process and won't do that.
This gives me flashbacks to lessons about von Hindenburg. An old guard who had belief in the process going by it even when dealing with someone who has obvious and sneering contempt for that process.
To be fair the situation in Germany was multipolar. Hindenburg wasn’t a huge fan of democracy or especially of one run by Catholics, liberals and socialists and just saw the nazis as a lesser evil..
I mean under what idea is that part of his official duties? If it's not it's literally exactly the same as before. Biden can do this at literally any moment. This court case doesn't change his ability to make unlawful moves.
After today, if a federal judge arbitrarily decides "it's not", well... it's not.
I suppose if they really wanted to give a reason they could say he's a flight risk or something, it doesn't need to be valid with today's ruling.