They are used for VMs because the load is pretty spiky and usually not that memory heavy. For just running single app smaller core count but higher clocked ones are usually more optimal

>Anyway, I wasn't able to test using proxmox or vmware on there to split up cpu/memory resources; we decided instead to just buy a bunch of smaller-core-count AMD Ryzen 1Us instead, which scaled way better with my naive approac

If that was single 384 (192 times 2 for hyperthreading) CPU you are getting "only" 12 DDR5 channels, so one RAM channel is shared by 16c/32y

So just plain 16 core desktop Ryzen will have double memory bandwidth per core