Look up how many refueling launches are required and you'll see the problem, especially because no matter if Elon says so, the upper stage will never be reusable, even if caught.
Every moon mission will require that they pre-build a HLS and probably 15 full stacks.
Ridiculous.
The Space Shuttle was reusable, and SpaceX is using an improved variant of the Space Shuttle heat shield, so it seems quite certain that Starship will be reusable. The question is more: how much refurbishment will it need? The Space Shuttle required extensive amounts. SpaceX will likely be able to improve on that a lot, though it isn't clear how long it will take.
Even if I'm wrong, though, it wouldn't invalidate the point I'm making in this thread: BO's Mk2 has the exact same issues in a more complex architecture.