Also .NET integration has the issue it doesn't work in all target platforms, that is why Capcom and Unity have their own compilers to native code. Even when Unity finally adopts modern .NET, Native AOT naturally doesn't cover game consoles.
.NET can generate the code, but your game won't pass certification if it runs machine code generated by something other than the officially provided C/C++ tool chain.
They have their own in-house fork of modern .NET, integrated into RE:Engine.