Rapid turnaround is not demonstrated. Nor is it even, in fact, planned, in any real sense. I.e., to be clear, there is no evidence that they have any idea how to achieve rapid turnaround of a Starship orbiter.

(Superheavy is a different story.)

All this turns on the design of the heat-shield tiles. Those we have seen are basically the same as on the shuttle. Each individual tile needs a great deal of personal attention before and after each use, including squirting in some goo that will boil off on the next flight. Many will need to be replaced, each flight.

So, turn-around time is weeks, minimum. More probably a month or two, or three.

It is conceivable that a future version of Starship will have a heat shield that needs less attention. Maybe a fabric shroud in place of tiles, over most of the hull, will turn out to be practical. If that happens, it might get possible to turn around a re-entered Starship faster. But that will require entirely new development not obviously begun.

I will be happy to be proved wrong.

Despite all of the above, even without quick turnaround or even re-usability, Starship is obviously overwhelmingly superior in every conceivable way to Artemis/Ares. NASA has the unenviable chore of trying to unload that turkey on some commercial contractor to get out from under the obligation to pour ever more treasure down its gaping maw, endlessly. If NASA succeeds in selling it at a penny on the dollar to Marietta, and leaving Marietta to try to find someone, anyone willing to pay for even a single hull, we can all breathe a sigh of relief.