yes but the majority of wealthy people would be satisfied with few million of real estate for personal use. RE investing would drastically change if incentives change

Fair point. I'd be satisfied nonetheless, because the land-ownership component of real estate investment is rent-seeking, that gains the holder value without generating value for society at large. If investment was redirected from land buying to purchasing other types of assets, it would lead to the production of more value in the economy, as unlike land, most asset classes involve man-made resources in which rising demand leads to rising production.

For example, if fewer wealthy individuals bought sprawling estates, and more bought high-rise apartments, we'd see more production of the latter, which would increase housing concentrations in high-productivity urban areas, and in doing so, apply downward pressure on rental rates in areas which offer the most economic opportunities.