People can spend time at the coast without owning a second home that sits empty most of the time.

Historically, we used hotels to visit places we spent limited time in.

(Or you can camp, visit friends, etc.)

I was replying to the vacation home part but the airbnb part. And regarding hotels they also drive up the price for coastal properties. I guess that is not as obvious for people to comprehend as they see an airbnb'd apartment and think "I could live there" while that doesn't go for the hotel. When really it's the lots they should consider.

Hotels are designed for short-term stays, and are regulated and taxed on that basis. (This includes such things as zoning, building code compliance, etc.)

Units converted to AirBnBs were not designed for short-term stays or taxed on that basis, and generally AirBnB only exists because it leveraged regulatory arbitrage quickly enough to grow to the point it could lobby for changes to the law. But after multiple studies in multiple cities confirmed that only a handful of investors benefited from loose unregulated short-term rentals, the pendulum began swinging back towards regulating them like the hotels they are.

It can also void your homeowners insurance to rent your home out on Airbnb.

There have been articles about this. It sticks in my mind because I used to be in insurance.

Residential buildings were not intended to be used this way and all the policy and infrastructure points to "No, really, you weren't supposed to use this as a commercial vehicle. That's not what all of society agreed to for this piece of real property."

I've always suspected that being an Airbnb host appears to be much more profitable than it really is because hosts are not properly insured.

I wonder if it would even make a difference? I used to be a landlord in Scotland, and now am in Finland.

For landlord insurance I'd pay about £300/year in Scotland, and €60/year in Finland. I'd be surprised if there were short-term policies, as distinct from long-term-tenant policies, that we significantly more expensive than that.

The risk from taking on multiple short-term tenants with no real background checks is surely much greater. Especially given that the tenants have no real incentive to behave well or keep the property in good condition.

Some people do think the indigenous peoples that originally lived there should have exclusive rights.