> more expensive, harder to design, harder to build, carry less weight and likely uneconomical.

Compared to Starship, sure. But compared to the Shuttle? That's a pretty low bar that's pretty easy to beat.

Starship is basically the Shuttle done right. major differences: Methalox instead of hydrolox & solids. Stainless steel. Uniform tiles. Vertical landing. No cross-range capability.

Any or all of those changes would have made the shuttle better.

Full-flow staged combustion might be impossible without modern metallurgy. The Soviets had that in the 70s but the Americans didn't. OTOH the Americans had the F1 in the 60s and a new version of that would certainly provide suitable thrust to weight ratios. Kerosene means more frequent refurbishment, but still better than the Shuttle.

Vertical landing would be tough with 70s computing but certainly would be possible with 80s computing.