"In addition to increasing capacity and speed, the improvements in energy efficiency are noteworthy. With HBM3, the core voltage is 1.1V, compared to HBM2E’s 1.2V core voltage. HBM3 also reduces the I/O signaling to 400mV versus 1.2V for HBM2E. There will be further improvements in future generations, as well."

For CPU, and maybe not GPU, and when you look at huge dies like the Mx from apple, I wonder if CPUs with 16GB of cache, a few cores then no DRAM would be "realistic" (excluding the economic aspect).