It was common 20 years ago for people in their mid-forties to use the massive equity in their home to buy multiple properties for the rental market. House prices at the time were growing so they not only had someone else basically buy their house over 25 years they also profited greatly from the inflation in house prices. With the increase in prices they could increase the rent so the whole thing is a triple-whammy.
This didn't happen as much in other countries because other countries reduced the tax benefits for this scenario.
That's again trying to limit supply because that's obviously reducing profitability.
We need to increase supply, or decrease demand, or both. Nothing is done on this.
That idea is so bad that not even the governments of the world, money grubbers though they are, have signed up for it. It would create a world where no capital was for sale; any path from going from low-mid to mid-high income (apart from entrepreneurship) would be closed off and a whole bunch of new 'unrealted' problems would turn up because purchasing power would be diverted away from people who care about the future to people who consume in the present.
Capital gains is a wealth creation engine whereby people voluntarily choose not consume in order to create things that other people want. There is a pretty decent philosophical case for not taxing capital gains full stop. There is probably a great reason why in practice it would not work, but as a principle it is like corporate tax - disincentivizing and de-emphasizing people who would otherwise give their resources to others.
If you want to wage class warfare, consider inheritance or land taxes. My personal preference would be to go one step more subtle and wind back the bail-outs and money printing. Capital Gains taxes are not the lever we need, the risk of collateral damage to the investment ecosystem is too high and by the time the damage is obvious enough to unwind a change we'll be 10 years in and facing a dearth of long term planning.