Comment by Tuna-Fish

Yes.

Not because rom is better than flash, but because the critical part is distributing the memory with the compute. Mask ROM is just the densest way of embedding memory with logic. Instead of having a large pool of memory connected to the separate execution units with a bus, each execution unit locally has the rom that it uses. Data movement is >90% of energy use in modern ai accelerators, removing it as far as practical is how they get performance and silicon and energy efficiency.