This is largely a function of both frame rate and IPD.
The latter is one of the reasons why I feel Meta has done an absolutely huge disservice to VR adoption by making the Oculus series fixed IPD. They claim to be able to software compensate, but my experience is that IPD on a headset being even just a millimeter or two physically off makes the difference between a comfortable VR experience and one that leaves me with a headache after the fact.
The fact that they reduced screen refresh rates on the Oculus S and the original Quest didn't help at all either.
I've had an Index since shortly after they became available and can use it hours at a time without any sort of discomfort provided my GPU is able to serve up enough frame rate for a particular title. Available GPU power is holding back VR currently more than anything, IMO.