This. I repurposed a dell t3500 with a xeon x5650 (https://ark.intel.com/products/47922/Intel-Xeon-Processor-X5...) GTX1060 6gb and samsung evo ssd, and the thing is still quite fast running ubuntu Mate and windows 10 LTSB.

The only real obstacle is the lack of NVME support. SATA3 is a bit of an upgrade bottleneck on these old systems, but even software development on this box was just fine with a fast ssd.