It was already a dire situation running a Mac with eGPU or a Hackintosh even before the RTX 30-series announcement, and much more dire after that. The likeliness of Apple allowing NVIDIA to produce Mac drivers again is close to zero. It’d be nice for AMD to be able to compete with GPUs again.
What do you even do with a GPU on a Mac these days? I guess there are a decent amount of games now, but it seems like it'd be mostly limited to "creative" stuff since CUDA is out of the question. Imagine how much more dire it's going to get once Apple has ditched Intel. Are they going to continue using third-party, discrete GPUs? You definitely won't be able to use one off the shelf (at least without flashing the car…
Intel integrated GPU has a huge downside in laptops - offloading to it causes it to heat up and since, so close to the CPU...CPU gets heavily thermal throttled. That's true for any laptop that isn't inch or more thiccc.
Also, Apple will be switching to their own GPU in a few years.