It literally is quite that simple. I can tell you from experience via friends and acquaintances that tourists are crushing the locals out of Barcelona and Amsterdam. And I expect the same to be true of Warsaw or Berlin.

And its not just tourists. ASML has completely destroyed the housing market in the Brainport region. They're planning to hire 20.000 more people, but with The Netherlands currently being in one of the most severe housing crises in the world, these expats just end up pushing everyone out of the local housing market because they can overbid on houses / rental properties so much.

ASML has woken up to this and is underwriting affordable housing developments, but only at a clip of 1500 per year. So yeah, the locals are not exactly happy, even if it is good for The Netherlands and EU as a whole.

Frankly, I expect the next decade or two to be about harsh protectionism. People are really, really tired of globalisation eating the world.

Barcelona has immigration problem, not tourists. The same with Warsaw and Berlin.

Meaning they've become gentrified by rich foreigners?

Medieval places that have nowhere to expand to (Venice, Dubrovnik) are hit extra hard.

That said, I visited Rome 20 years ago and a year ago, and what used to be fairly live city center is now one writhing mass of bodies.

Japan closed their borders to tourists during COVID. If it's as simple as you say, then they can do it again.

They won't because you couldn't get a majority of their populace to agree with you, which doesn't necessarily mean it's incorrect but does at least mean it's not simple.

I suspect the people profiting off tourism aren't the same ones who gets squeezed out by it.

Who's holding people's hands and preventing them from building new houses? It's possible Netherlands genuinely has very little land left, but the "housing crises" in most other places are completely made up. Housing is either affordable or an asset that appreciates, it can't be both.