Also, we don't tax the capital gains of sold additional homes enough. We should tax those gains to the extent that it isn't profitable to own and sell additional property.
If you agree that renting shelter is important to many people for valid reasons, someone or something has to be able to own that property that you call "additional" and others call "the place I live".
Landlords should make money for the services they provide: upkeep of the building, providing living space, etc. But real estate capital gains do not come from productive investment such as in a productivity-boosting new company. Capital gains in real estate are unproductive rentierism, and are a drain on the economy.
One thing that all economists can agree on, from Adam Smith to Ricardo to Marx, is that land rent is bad and should be taxed away. Capital gains on real estate sales are a great way to do that, while preserving profit for those who productively improve land and rent it out to others.
Because we don't, much of what we call "capital gains" are "return of capital, measured in a greater number of now less valuable dollars". Return of capital should not be taxed.
Real estate land gains tend to dwarf any inflation effect, so it's a pretty minor tweak to include, anyway.
Tax treatment of depreciation of buildings is also a big factor here.