Nitpick: you're probably thinking of directly intervening with the economy through regulations and subsidies, but isn't disrupting the housing market technically going to be a massive economic intervention in practice? As in, kind of by definition?
Also, I'm not sure if it's actually that easy to change the laws surrounding housing in such a way that pushes back against wealth accumulation.
It's hard to actually address Piketty's inequality at all if people think it spawns from something fundamentally different from land/real estate appreciation.
> I'm not sure if it's actually that easy to change the laws surrounding housing
Totally agree, but I don't mean to make any claims about how hard it would be, only that it would actually address the thing in question, whereas other interventions would not.
Of course such taxes wouldn't automatically create housing, but it definitely disincentivizes hoarding it, and allows the state to capture more of the accrued wealth to redistribute it. It makes real estate look like a less enticing holding and would make people less entrenched in defending its value, etc.
Instead, people want to take Piketty's conclusion, not look at where the r > g comes from, and then go on to fuss about with other things (like forms of wealth distribution, taxes, etc), instead of directly addressing the one thing that causes most of the r > g, which is housing, which does not need massive economic intervention to solve, but something entirely different (relaxing of building laws, etc).