I think the right question is: what would they want from the plebs? And the answer will be nothing.

Right now they want the plebs' labor, which is why things work the way they do.

> The Phools and so the plebs were exterminated, then what?

Is that a reference to this? https://press.princeton.edu/books/hardcover/9780691168319/ph...

> Perhaps we'd finally have Star Trek economics, but only for them, the "owners". Better be an "owner", then.

I don't think we'll have Star Trek economics, because that would be fundamentally fair and egalitarian and plentiful. There will still be resource constraints like energy production and raw materials. I think it will be more like B2B economics, international trade, with a small number relevant owners each controlling vast amounts of resources and productive capacity and occasionally trading basics amongst themselves. It could also end up like empires-at-war (which actually may be more likely, since war would give the owners something seemingly important to do, vs just building monuments to themselves and other types of jerking off).

That the Earth of Star Trek is populated by only the descendants of the capital holders. Everyone else was directly or indirectly exterminated.

Then they created an egalitarian tech utopia for themselves.