Edit for clarification:

For example, the destruction of local environment is a known problem for places such as Machu Picchu and Venice, to the point where you now need to reserve and pay for a visit to the city of Venice [0]

As population gets higher more and more people want to visit the top destinations, and when a new one gets "found" it gets flooded (see Dubrovnik after Game of Thrones hype)

Because of physical limitations these experiences don't scale - there's a finite number of destinations in the world and an ever-growing population.

[0] https://www.nytimes.com/2022/07/01/world/europe/venice-touri...