Quadro and Tesla cards might be a different story. I would still like to see concrete FLOPS/$ numbers.
4090 peaks out at around 550w which means they can run 5+ of their Max chips in the same power budget.
A 4090 is $2000. Apple can probably get 5 chips on a custom motherboard for that cost. They'll use the same amount of power, but get a lot more raw compute.
Crazy times.