By doing that, ultra-wealthy _are_ realizing the value of their investments without being taxed. That's how this wealth is being accessed, and that's a large component of what drives these ultra-low tax rates for the ultra-wealthy.
Also I don't understand how a growing population leads to increasing prices, while there's so damn much unused land? Either there is enough new land, then people eventually spread out (and prices revert to the CPI, to the cost of construction), or there isn't enough land and homelessness increases as more and more people are completely priced out. Right now nearly every country is in the first situation.
I'm sorry, but HELOC is really just dumb.
It's not binary. People like to live near other people in cities. Demand to live close to one's job, friends, activities, and loved ones drives up prices in dense areas even with unlimited room to expand elsewhere.
Desirable locations are desirable even on an infinitely-sized map.
The reason that works is that basis is reset at death.
The free step-up in basis at death makes no sense for the very wealthy. The rule originates from the difficulty in determining the basis of assets of dead people. The very wealthy have accountants that track this.
Warren Buffett can pay capital-gains tax AND estate tax.
That is a far cry from taxing unrealized gains as income which is what a lot of people seem to want to do.