Is it possible to run ARKit in simulator?

Not yet ... BUT ... Google might show the way.

You can run Android ARCore in the Emulator. I run it on my Mac. https://developers.google.com/ar/develop/java/emulator

ARCore and ARKit follow the same basic IMU-SLAM architecture. So I believe it is technically possible and I hope Apple follows suit.

ARKit uses the camera as well as gyroscope and accelerometer to map the world and get the device's relative position, so no you won't be able to use it in the simulator.

I suppose it is not possible because the basic requirement to run ARKit is camera access.