Yeah, for one, you can actually enter the palace and not stay outside. The numbers of visitors in versailles absolutely dwarfs british palaces. I'm talking 'more visitors[0] than the british top 10 combined[1]'. And the fee to enter is not cheap. 20€.

[0]: https://www.statista.com/statistics/991925/visitors-palace-o...

[1]: https://www.statista.com/statistics/373081/uk-royal-tourism-...