Few can match his weird charisma with the masses, even if they can better bend the government to their will. When strongman leaders die, they are notoriously hard to replace, so considering how Trump has torn down anyone with independent popularity while filling his administration with weaklings like Vance, the party will not stay in power without him. Even much of the right will be sick of the state of the economy, despite their unwillingness to admit that it was all their fault. This wave of fascism will die with Trump, and that's why nobody has succeeded in replace him over the last decade.
Besides, I think the oligarchs will want more stability after he's gone, and with the Democrats getting more corrupt every year, placing them in power will be a no brainer. Foolish liberals will believe whatever bullshit they're sold about "rebuilding our democracy" and "swinging the pendulum back," while some Gavin Newsom like corporat will be chosen as the next king. With the rise of China as the dominant superpower, they'll sell everyone on anticommunist bullshit that'll win over many of fascists that used to follow Trump. They'll likely continue throwing minorities like trans people and immigrants under the bus, but they'll be nicer about it and dress it up as "serious concerns" to give plausible deniability to people who thought Trump only went too far.
If that's what you mean by replace him with someone competent, then maybe you're correct. However, that'll be a distinctly different stage to what we have right now, and it likely won't last either for the very same reason that neoliberalism led to fascism in the first place.