What would really concern me about the GOP's future is that, beyond Trump, what does this party look like? Who ascends to the top? (no, JD Vance isn't gonna cut the mustard)
This is the problem with personality cults (I'm sure some will dispute the characterization, but if we're being honest, it is one).... when the leader ages out and / or dies, it leaves a massive vacuum behind. This party has currently wrapped it's identity in this one person, but there really isn't any evidence that "Trumpism without Trump" works at all.