I mean, its normal to use the instructions for floating point math even when its not actually vectorized, so they are in there all the time. And a 64bit target will tend to enable SSE2 which will get you quite a bit of auto-vectorization.

and anything in .NET land since .NET Core will have a ton of SIMD in it

Compilers do emit the instructions regularly, but they rarely manage to speed up the code much.