Do we make them give 20% of their unrealized paint to members of the public so they can make their own paintings, hoping they too will fetch $1m each?
If the IRS took control of 20% of the paint, borrowed against it to fund the state, but then the artist decided to quit does the government somehow force them to paint?
If the artist said this ahead of time and this was priced into the future value of their paintings (now worth $0 because there will be 0 paintings) does the IRS revalue their unrealized gains down to $0bn?