JD Vance doesn't popular enough to be the face of the party. There's going to be a massive power vacuum after Trump, hopefully one that irreparably fractures the GOP.
You would at least get the cult of Trump a lot less vehement about supporting everything Vance says and does, and therefore a lot of Republican representatives willing to push back against federal overreach instead of sucking up to them.
Trump: Don't worry, I didn't die.
90 % of the world: