Honestly, Apple seems to be on the right track here. DDR5 is slower than GDDR6, but you can scale the amount of RAM far higher simply by swapping out the density.
People did it with the RTX3070. https://www.tomshardware.com/news/3070-16gb-mod
To have more memory, you have to design a new die with a wider interface. The design+test+masks on leading edge silicon is tens of millions of NRE, and has to be paid well over a year before product launch. No-one is going to do that for a low-priced product with an unknown market.
The savior of home inference is probably going to be AMD's Strix Halo. It's a laptop APU built to be a fairly low end gaming chip, but it has a 256-bit LPDDR5X interface. There are larger LPDDR5X packages available (thanks to the smartphone market), and Strix Halo should be eventually available with 128GB of unified ram, performance probably somewhere around a 4060.
You're right: nobody's doing ML these days. /s
Look at the value of a single website with well over a million users where they publish and run open-weights models on the regular: back in August of 2023, Huggingface's estimated value was $4.5 billion.