The hard part of reuse is getting the thing back in flying shape. The booster part is actually just demonstrated, and this flight got us a fully-intact upper stage back, sans a few tiles lost to the wind and the landing being simulated.

I can see room for skepticism on their rapid reuse plans, but skepticism on practicable reuse alone just seems discordant with the demonstrated success.

The booster and most engines were reused in this test flight.