I have an app on the cloud and I refuse to pay for their cores for my back-end processing.  These older workstations with many cores and lots of RAM are just what I need to do my back-end processing.  I am using Ubuntu, a PCI-E M.2 SSD card for storage (database mirror).  This thing is more powerful than a $20,000 database server was a few years back (notwithstanding lack of IO).  I don't need a lot of IO, so lack of drives is not an issue, especially with PCI-E SSDs that you can pop in.  A 24 core desktop with 128GB RAM cost about 4-5K on current generation.  Going back a few generations and getting slightly slower RAM and processors is fine for what I am doing.  Amazing deals.