Actually many people seem unaware that .NET has supported AOT since the beginning.

The reason that they are unaware, mostly is that using NGEN requires really wanting to use it, as it requires dealing with strong named Assemblies, aka signed .NET libraries/executables.

It only supports dynamic linking, and still pings back on the JIT for more complex code sequences, its original goal being fast startup time for desktop applications.

Thus before .NET Native (UWP only), Mono (iOS/Android), and now Native AOT, doing AOT compilation on .NET was largely ignored, despite NGEN being available.