Here's why not: Because too much vacancies/transient inhabitants destroys communities.

A lot of shops etc depend on local customers. If there is too small a consumer base, these shops disappear starting a cycle that is detrimental to the neighborhood.

This separated from the assholes that drag their airport suitcases with hard plastic wheels across the pavement at all hours. Have weekday keg parties and all sorts of other shenanigans. Neighborhoods are for living, hotels and other accomodations are permitted for a reason.

The way it all started was people with a spare bedroom, which is fine. Then the residents will make sure that people behave and that the airBnB'ers behave.

Oh please, rents were increasing higher than wages for decades now, taking even bigger chunk of the pay of regular people. And Airbnb and Booking in tourist/business hotspots are to blame to a large extent for that.

It would already help a lot if they would spread out more. Malaga is not the only town in southern Spain, nor does it have any unique sights you should not miss. But that would require tourists to make an effort to seek out the less well known places and not just hop on a plane because there is a cheap flight offer.

You limit the hotel licenses. You then go hard on hotel inspections and revoke licenses or don't renew it from hotels that aren't up to code/standard. That way the available hotel rooms will go down. The number of licenses is limited by hotel category. That way you ensure a healthy mix of available room types and can still have all kinds of tourists in town. There won't be an issue with "big chains snatching up all the licenses".

Then for a time only people with a valid reservation are allowed to enter. You place checkpoints at the most common points of entry. That way you limit the number of potential tourists by limiting the available hotel rooms. It would also fix the issue of unregistered AirBnBs. It won't be perfect but you don't want to kill tourism just reduce it.

Locals and family of locals would be exempted from the limit. You just put some system in place to apply for that exemption for family. Since the checkpoints are only temporary (maybe around 6 months) the impact on locals and their family isn't too bad before it goes back to normal.

There will be a lot of media coverage about the closure and fewer tourists will come. The lifting of the checkpoints will barely make the news so things won't go back to how it was before. And the limit on hotel licenses is still in place, so the available rooms are limited anyhow. Naturally reducing tourism because fewer peope can book a room.

Well we learned from covid that musea and other tourist destinations can easily limit access.. so make more destination Limited entry with reserved cards. The cards can be free, and person bound. To avoid scalping.

I'm not saying this is THE solution, but there are a lot of smart people out there, if we express a desire to fix this, a solution will be though up that works.