For the longest time, single-socket servers were the bottom of the server hierarchy, using "server" chips weaker than what you might find on a desktop. There were even servers that used the Atom processor. These were departmental servers doing the most menial of tasks, like file and print serving.
But that's changing. Driven by high-core-count processors, and no doubt a desire to reduce costs, single-socket servers are getting some hefty workloads. AMD has led the way on this with its 32-core and 64-core EPYC processors that can do more with one chip than what a five-year-old dual-socket server can do. Dell has the servers available.