I’d suggest investigating single core performance. If you have the money, buy an i9-12900K (slightly faster single-core than M1 but much hotter) and do some testing on that. If my theory is correct, performance will be even better.
My next question would be if you ran the 12900K in dual-channel memory.
Ryzen is 2 channels; Epyc is 4-8 (depending on CPU). M1 has that stupidly fast/wide setup.
If your Epyc is one of the 4 channel optimized SKUs or is only running in 4 channel mode, you would get pretty close to the quoted ratios on a memory bandwidth test.
Correlation, not causation, but worth looking into.