It was literally impossible for most holders to sell at the price when the Bitcoin Cash fork happened because none of the exchanges were accepting deposits. Part of the reason the price was so high then was exactly because people couldn't sell; it dropped as soon as deposits opened. (Since this happened at different times on different exchanges, the prices diverged quite a lot too.)
It's literally impossible for most holders of pre-ipo options to sell them, or their stock, but their tax bill is due the day the leave their employer, not the day that those options/stocks become liquid.
Surprise, tax law isn't fair. Surprise, nobody is looking to change that.