Four benefits on the recording server I can think of. These all center around the ability to have lower-cost, lower-powered systems with maximum compute resources, handling many hundreds of cameras without sacrificing features.
1) Milestone is building a framework for 3rd-party server-side analytics and server-side analytics require decompression of the video. Having loads of low-cost compute available via CPU, Intel Quick Sync, and NVidia is helpful.
2) Milestone users have the option to do motion detection on the camera or on the server. Most choose on-the-server as it allows a variety of benefits such as super speedy Smart Search, set-up of motion areas in the Management Client, etc.. This also requires decompression of the video stream.
3) Super powerful, low-cost, and/or low-power, recording servers that can be built using either Core Series or Xeon builds.
4) A way to increase the power of existing recording servers without having to rip-and-replace with new servers. One current use-case might be the Intel Spectre Meltdown flaw in which every Intel system in existence will likely see some form of decreased compute power as patches are released. If you have a server that is already loaded down, the next Windows update might result in the server that is actually overloaded. An easy, low-cost fix might be to drop in an NVidia card or two.