Imagine you're a startup founder who has a high-flying startup. You own 20%. It just got valued at $800,000,000. Now you're worth $160,000,000 ON PAPER. That's awesome. But it's not the same is being rich.
Imagine your salary is $150,000. With the Warren plan you now owe $2,200,000 PER YEAR in taxes from cash you don't actually have. So you now what, sell your company? Try to secondary? Congrats you just got taxed real money on fantasy paper gains that you never realized.