Harris unveils plan for 28% capital gains tax, softening Biden's proposal for 40% rate

Mostly yes.

You get people selling off companies or several depreciated rental properties, and they get hit with the tax and can't get out of it.

There are some circumstances that they can manipulate though. When the stock market crashed in 2008, people sold off at enormous realized losses, sat on the cash for thirty days to avoid the wash rule, and bought right back in at the same low prices.

That created years worth of carried over losses that enabled them to recognize capital gains at zero tax.

It's a reasonably common strategy called loss harvesting.

Certain flavors of stock options appear to be tax free at time of sale, but this is because the initial grant was deemed W-2 wages and was taxed when it was issued at ordinary income rates.

Yes, but no. Yes if you sell your asset at a gain you pay taxes. However, if you don’t realize your gain and instead use your asset as a collateral in a loan, you don’t pay taxes. That’s why the rich pay no taxes whatsoever. For instance, Bezos has 2 bln in outstanding loans. As a collateral he uses his 200 bln share in Amazon. He never pays taxes.

The proposal by Harris would fix this and tax gains prior to realization. If she succeeds that is a much bigger deal than whether the rate is 20,30 or 40 percent.