You forgot about people who live there all year round. You know, the ones who work, maintain services, offer food, have children who will keep everything working.
Spain shouldn't be a big hotel, it is also the country of people who live all year round.
Spain has vast areas of unused buildable land, especially the South. It's not like land is a scarce resource there. Me buying a house won't cause someone unable to buy another one in the area. They can build it nearby if they want. The problems there are not caused by tourism as there is enough space for everyone and then some. Telling someone who has to actually work to be able to spend a few winter month in the sun that Spain should be for people born there while benefiting from EU (that means free movement of people among other things), trade and first of all tourism money is just the most arrogant entitled attitude I can imagine.
There is plenty of industry and jobs in the north.
If the south keep relying on tourism they will keep this misery going.
I don't care if you are born here. I only care if you work and contribute here. Tourism is killing people.
Look at Barcelona. Before the Olympics it was a amazing place to live. Now it's rotten and prostituted to expats, tourists and poor people who go there to work in inhuman jobs paying unpayable rents.