The Shuttle aimed for a unrealistic number of Reuses. I mean They aimed for a level of reuse equal to that found in a Boeing 707 with a flight a week. Each shuttle being rated for hundreds of flights and a very simplified servicing and turnaround, In reality Everything gained more and more complexity. The failing of the heat protection, the redesign of the SRB the destruction of the ET every launch kept driving the costs up.
By Contrast the reusability being aimed for for SpaceX and other concepts like Vulcan and Dreamchaser and others is much more scaled down.
first Although Musk as Spoken of unrealistic 1000 reuses It's more likely that the number of reuses will be a Dozen or so, this is realistic as the SRB proved one of the more reusable parts of the launch.
by keeping the intended number of recycling down the stresses placed on the launcher drop. Additionally for more extreme missions Falcon is disposable. Infact the last recovery was a surprise. they set it up but mostly just to see how close it could come.
Next is the scale of the capsules. The Dragon capsule, and Dreamchaser are far far smaller then the shuttle. The huge scale of the shuttle demanded large repair costs especially to the thermal tiles.
Remember the Hull of the Shuttle was Aluminum it requited the thermal protection system which was thousands of tiles that had to be replaced every time. And those Tiles were the ultimate failure of the shuttle. before the Columbia Tragedy there were other incidents of Debris damaging the Tiles Infact It was bassically Shear luck that kept it from happening sooner.
STS 27
On recovery the shuttle was found to have nearly been destroyed the only thing that saved STS 27 Atlantis was a singular Steel plate sandwiched between two aluminum plates. the heating had melted though the first Aluminum plate and the second Steel Plate but the heating had stopped before the final plate was melted.
by being smaller the heat shield are much smaller with a smaller number of potential for problems and need for repair. also note that in launch these capsules and space planes are placed on top so facing away from potential debris on launch.
Additionally Space X and Blue Origin are not done yet both are still refining there designs using lessons learned from there past recoveries to change the design. Remember in the past 5 years Falcon 9 has been redesigned a number of times and will continue to do so It's not a fixed mass production yet.