A beefy GPU which can't hold models in VRAM is of very limited use. You'll see 16 GB of VRAM on gamer Nvidia cards, the RTX 5090 being an exception with 32 GB VRAM. The professional cards have around 96 GB of VRAM.

The thing with these Apple chips is that they have unified memory, where CPU and GPU use the same memory chips, which means that you can load huge models into RAM (no longer VRAM, because that doesn't exist on those devices). And while Apple's integrated GPU isn't as powerful as an Nvidia GPU, it is powerful enough for non-professional workloads and has the huge benefit of access to lots of memory.