First up, I am not claiming that casts are of equal importance to the actual skeleton. I am annoyed however I come across arguments by anti-collectors that it is not feasible for museums to cast fossils in private collection.
The recent rediscovery of the "Proteosaurus" casts should prove beyond any doubt that while a cast isn't on par with the original, they can still provide invaluable research data to paleontologists.
https://royalsocietypublishing.org/doi/10.1098/rsos.220966
I hope that more paleontologists can consider partnering with private collectors and vice versa. I am sure the majority of private collectors would be happy to loan their fossils to museums