Are there laptops with an RTX 3090 or Quadro RTX P8000?
No.
Not yet 😂
No.
The battery would be empty after 1 second…
That won't happen for the time being, and if it did, it would be far too expensive.
No, it does not exist. But there are some with a 3070 https://www.alternate.de/Nvidia/RTX-3070-Notebooks
and apparently some with a 3080 but I didn't find any.
But even for a laptop with a 3070 one flips through 2000 euro and more. So with a 3090 you would probably move in areas of 3000-4000 euro.
I don't know if a laptop is worth that much money.