* Residential real estate market size was $33 trillion in 2018, of which about 80 million units are privately owned and 60 million units are not.
* Commercial real estate market size (Office buildings etc.) was about $15 trillion.
But even regardless of that, it doesn't change the numbers. The majority of the increase in real estate prices goes to corporations rather than individuals. An explanation of why it happens doesn't change that it does.
Some cities and countries (e.g. Vienna, or the Netherlands) provide public housing through gouvernement and/or not for profit organisations (i.e. with 0% returns), to a large part of the population. These places also have some of the lowest inequalities, which seems to validate the parent's message.
Make it cheaper and easier to build new housing and you'll see a lot more new housing.
So zoning contributes substantially to wealth inequality.
They were saying that most of the imbalance if from housing, that a lot of people own, not just from owning stocks/bonds/etc...
Removing housing reduces returns seems like a tautology: if you remove one of the best-returning asset classes, returns are lower.