Why dedicated server build as single binary?

I’m build Linux Dedicated on Windows, and it produce ~700MB single executable binary, it’s fine?
Can I build dedicated server with shared dynamic libraries? It will be more optimized for many server instances?

700 MB size is largely taken by the debug info. It is possible to strip it out, but I wouldn’t recommend that since you will have much worse callstacks - which is essential for understanding what went wrong since some crashes can happen only after several hours of play or only when N people are connected. When you are making a modular build, the size will be similar (if not larger) since all the shared libraries will also have debug info.

As for multiple instances, there should be no difference - when the same binary is run multiple times by the same user, only the changed pages private to each process should actually take physical memory, the rest of the mapping can be shared.

But why the windows build (same configuration in VS: Development Server) is 90MB, and the Linux one is 700?