Older Xeon systems (v3, v4) give you oodles of cores, main memory channels, and PCIe lanes. Single-threaded performance isn't great, but for multi-threaded workloads they're great value for the money and power.
Compare those threadripper systems to R730, T7910, and T7810, with E5-2680 and E5-2690 processors, and see which makes sense to you and your use-case.