This tendency started long before airbnb and foreigners started buying a "big majority of properties".
People have been moving to cities for decades now. Many of humanities recent developments make much more sense at scale so people are going to places with that scale. Some prefer a quieter environment and don't move but most people rather have opportunities, jobs, services, etc and all that is made much easier when lots of people are concentrated in a smaller area.
People have been moving to cities for decades now. Many of humanities recent developments make much more sense at scale so people are going to places with that scale. Some prefer a quieter environment and don't move but most people rather have opportunities, jobs, services, etc and all that is made much easier when lots of people are concentrated in a smaller area.