This is true, but that is only an advantage when running a model larger than the VRAM. If your models are smaller, you'll get substantially better performance in a 4090. So it all comes down to which models you want to run.
It seems like 13b was running fine on 4090, but when I tried all the more fun or intelligent ones became very slow and would have peformed better on m3.
Yes, M3 chips are available with 36GB unified RAM when embedded in a MacBook, although 18GB and below are the norm for most models.
And even though the Apple press release does not even mention memory capacity, I can guarantee you that it will be even less than that on an iPad (simply because RAM is very battery-hungry and most consumers won't care).
So, therefore my remark: it will be interesting to see how this chipset lands in MacBooks.