The only people that knew in advance that higher capital gains tax rates - up to 28.8%* - would take effect today were the politicians writing the law. That is, they got to take advantage of lower rates. Which is pretty useful, following a year of their stimulus-fueled asset inflation.
At least, the new top rate is a lot lower than the 43.4%* total top tax rate that Biden proposed.
* including NIIT, but excluding state taxes of up to 13.3%