It's the same fundamental reason that Forza and Grand Turismo is more popular than VR iRacing: For the vast majority of people, the goal is FUN, not authenticity or """immersion"""/fidelity and accuracy of simulation. A game that is "simulatorish" and easy to use with a controller, and has lots of average cars that normal people can connect with.

VR has proven itself pretty much only in VR racing and VR flying, where it provides an impossible to compete with improvement in experience, but at a huge cost and COMMITMENT. It takes effort to put on a headset, set aside some space, and commit to being "away from reality" for a bit