- It needs extremely high-bandwidth controllers, which severely limits the amount of memory you can use (Intel Macs could be configured with an order of magnitude more ram in it's server chips)
- ECC is still off-the-table on M1 apparently
- Most workloads aren't really constrained by memory access in modern programs/kernels/compilers. Problems only show up when you want to run a GPU off the same memory, which is what these new Macs account for.
- Most of the so-called "specific workloads" that you're outlining aren't very general applications. So far I've only seen ARM outrun x86 in some low-precision physics demos, which is... fine, I guess? I still don't foresee meteorologists dropping their Intel rigs to buy a Mac Studio anytime soon.