In case of any doubt about Trump's motives, money is always a safe bet. I have long believed that he will stay in politics after losing the 2020 election just to collect donations (and launder them through his properties etc), just didn't think he'll do it so blatantly. But why not, he owns the party, he can do no wrong.
I think I see what you're doing here, encouraging Republicans to challenge the usual groupthink, but really I don't think Trump owns jack shit anymore. He only has a future as a ghost now, but his followers desperately cling to the belief that he still inhabits a corporeal form politically. He does not.