Intel and Qualcomm are doing this, although Intel uses HBM and their hardware is designed to do both inference and training while Qualcomm uses more conventional memory and their hardware is only designed do inference:

https://www.intel.com/content/www/us/en/products/details/pro...

https://www.qualcomm.com/news/onq/2023/11/introducing-qualco...

They did not put it into the PC parts supply chain for reasons known only to them. That said, it would be awesome if Intel made high memory variants of their Arc graphics cards for sale through the PC parts supply chains.

I guess that would be an NPU combined with LPDDR. Basically any Windows Copilot Plus approved device.