There’s easy solutions to that if it ever becomes a problem (the easiest is a vacancy tax) but it’s not currently a problem in the US as can be seen from the fact that places which have built more housing in the past decade or so have much lower rents than similar places that haven’t built as much housing.
Arguably it is already a problem. NYC's "Billionaire's Row" is crammed full of apartments built for the sole purpose of investment and remain vacant. Imagine how many homes for "regular" people (yes, it's Manhattan, they'll still be expensive) could have been built there if there wasn't a financial incentive to bury money like this.
These skyscrapers buy "air rights" from neighbours to build high which takes away even more homes.
NYC's primary problem is having the worst housing production rates of any major US city (aside from a handful that are economically struggling and have low production from outright lack of demand), and the downstate/LI suburbs being exceptionally bad as well.
The rest is basically irrelevant. Every one of those few "billionaire" buildings could be 1-bedroom market rate units at 100% occupancy instead and it wouldn't do anything significant for the overall problem.
For one example of how broken NYC policies are: 60% of residential lots aren't zoned for anything over 2 stories. The city needs to have much of it moderately upzoned to get decent (and decently distributed) housing development, not to somehow start building affordable skyscrapers in Midtown.
Places like NYC and London fit a kind of niche where there is a market for this sort of opulence/money-laundering. But if you, like, sit on a bunch of commercial real estate in Des Moines Iowa, turning it around into a $50 million apartment for the Saudis is not a real possibility.