Until a few weeks ago I would have said the same thing. Maybe it is true, but after watching the GOP cave at every point where they could have made a stand, I can't say staying with them is the answer either. I guess I have until November 2022 to figure out what direction I'm going to take.
The problem is the down ballot elections in each state for all of the federal, state and local candidates who usually ride the coattails of the president. That's where it gets difficult. The party organizations and structures are so ingrained in the politics, that to separate the two is difficult.
If Trump forms a new party, the elected officials of the existing Republican party who support Trump need to be absorbed into it and the rest of the Trump haters, Never-trumpets, RINOs, Deep Staters and Uniparty traitors need to be destroyed.
Because they will undermine and sabotage a new party and Trump, quicker than anything.
How that's done is above my pay grade.