I asked this question myself very often. You are the first I read who's having serious doubts here as well. Anyone who knows more about this topic?
I started riding the CV1 as soon as it came out, switched to the Rift S and after a recent check-up with the ophthalmologist I didn't have to change my glasses. No problem with VR, and for the harm due to VR, I was sick at the beginning, but after several sessions, from short to very long, always increasing a little more, I no longer have any worry.
My eyes tell my brain that I am moving while the vestibular system in the ears is signaling to my brain that I am not moving, hence the "motion sickness" which causes discomfort in VR, except that the brains learns and finally understands that the eyes lie to him and so he adapts and we are no longer sick, so for me it's OK for VR, and definitely worth it!
it's not easy to write in English, I'm Belgian and I speak French, and you know that French speakers are very very very very good at languages! ;-) and so, sorry for the approximations of the language (and also for me the opportunity to thank Racedepartment for accepting the whole world on their website, the best in the world!)