That is typical of workstation and server chips. The goal is more cores at the same power consumption for multithreaded workloads, not necessarily per core performance. They'll have their boost clocks, but essentially they are guaranteeing every core, max load, to run at that speed within the TDP.
If you want the best of both worlds, Intel makes plenty of high clock frequency Xeons with 8 cores. E5-1680 v4 3.4 up to 4.0, and I know from experience they'll often boost over that for single threads. They have some pretty high core count 24 core or so chips that boost to 3.4, but they'll have that same 2ish Ghz base clock.
Though at this point the i9-7980XE would be the best mix between core count and core frequency (Though they might need to make some fancy motherboards and power supplies with thicker gauge wire, some of the reviewers were pulling nearly 500W through the socket, but getting it around 4.5Ghz)