I'd wager the number of workloads that'd actually take advantage of operating on entirely different data on a per-thread basis is much, much lower than ones tha

I'd wager the number of workloads that'd actually take advantage of operating on entirely different data on a per-thread basis is much, much lower than ones that benefit from massive L3 cache. And note that the infinity fabric and memory controller don't run on the same clock. The fabric tops out at ~2200 (though testing shows sweet spot at 2033 usually) and the memory controller usually tops out at ~3100 (DDR5-6200).