It's worth noting now there are other machines than just Apple that combine a powerful SoC with a large pool of unified memory for local AI use:
> https://www.dell.com/en-us/shop/cty/pdp/spd/dell-pro-max-fcm...
> https://marketplace.nvidia.com/en-us/enterprise/personal-ai-...
> https://frame.work/products/desktop-diy-amd-aimax300/configu...
etc.
But yes, a modern SoC-style system with large unified memory pool is still one of the best ways to do it.