The hull shape was very complex. Tiles on Starship are mostly identical; the massive number of SKUs involved in the Shuttle heat shield meant there wasn't a lot of mass production.
(Starship still has unique tiles near flap joints and edges, but the main hull itself has mass produced tiles.)
Didn't help that Shuttles had design differences between them as well due to the lessons learned and new technology developed between when they were built which resulted in having differences both internally and externally. Even the heat shield layouts were different.
Who says anything about heatshield tile being revolutionary? The whole package is, however -- Raptor engine, reusability, refueling, mass production, and so on. Together, they allow low cost, fast turnaround time launch service.
As for a different approach, try Stoke's active cooling solution:
(Starship still has unique tiles near flap joints and edges, but the main hull itself has mass produced tiles.)
As for a different approach, try Stoke's active cooling solution:
https://www.stokespace.com/news/building-rockets-to-fly-and-...