4 x DGX Sparks vs AMD Epyc 9xx5 system

Excerpt

I see a lot of people buy DGX Sparks, and turn them in to clusters to run large models. Wouldn't it be better to invest $16k into an AMD Epyc server with 768GB or even 384GB of 6000Mhz DDR5 ram, and let's say 2x3090s or 5080s, instead of 4 DGX Sparks with 512GB of ram? Epyc's theoretical bandwidth is around 576GB/s, DGX Spark's is roughly 273GB/s. Based on a quick check, both systems are worth around $16k. Please help me to understand this logic, are there benefits to having DGX cluster instead