Unfortunately the wealthy tend not to want to be taxed and they're not averse to fighting back. They've learned that they need to lobby even small local tax-raising authorities to obstruct these kinds of actions. In Wales, local authorities are allowed to raise a local tax premium of up to 100% on holiday homes [1], but few, if any, charge a premium of more than 50%, even in affected areas considered to be in crisis. There's also a loophole that a second home can be declared as a holiday rental property business, without any real intention of letting it out. Welsh authorities work hard to police this by asking to review evidence of lettings (I know this as I own a legit holiday rental property in an affected area) but the enforcers need extra funding to police the tax dodgers.

I don't dispute your underlying point that punitive taxes are a big part of the solution, but I take issue that it's an easy or overnight fix unfortunately because of the interests aligned against imposing them.

[1] https://gov.wales/welsh-government-announces-three-pronged-a...