The whole shuttle designs was simply not a good one, it has a lot of compromises and false assumptions. The Soviet version where you simply have a space plane

The whole shuttle designs was simply not a good one, it has a lot of compromises and false assumptions. The Soviet version where you simply have a space plane on the side of a independent booster was much better design that had much broader use case. It would have been much easier to build ISS if you had that capability. Remove the Solid Boosters and make the Core Booster better to further reduce risk. Once you are there you can just make the first stage land like SpaceX Falcon 9 does and have the Orbiter land like a plane. Even better to put the Space plane on top of the booster, rather then the side to reduce risk. And if your at that point, you realize you don't need the massive cross range capability, you can remove the massive wings. Then you are already pretty close to SpaceX Starship design.