Because prisons are for poor people. If it happens, he'll end up in a "prison resort" that has all the amenities he wants on the technicality that he can't leave.
So the EU has a member of the parliament who is in prison for membership of a criminal organization (which commited murder). He was still allowed to travel to Brussels and Strasbourg for his work. Really messed up. But I can imagine the US doing something similiar with trump.
The guy is called Ioannis Lagos if you want to look it up.
IIRC, he was allowed to travel to Brussels and Strasbourg only before he was convicted in 2020. Right after he was convicted, his immunity as a delegate of the EU parliament had been lifted, he was extradicted to Greece, and he is now in prison. He still gets paid as a MEP, though. I hope nobody is stupid enough to vote for him again this Sunday.
I just remember when Trump's DOJ put together those posse groups to roll up on people protesting during the BLM stuff. All of them were either from ICE or prison corrections. They're entirely in the pocket of the GOP.