I’ve actively been encouraging friends and family to try it and my experience is that motion sickness hits about 18/20 people within 30 minutes of play, depending on the game.
However I’ve noticed that my friends who have played a lot of computer games (in particular fast paced FPS) tend to fare better, and also that the sickness goes away with practice. I used to get it too but now I can beatsaber for literal hours without discomfort.
The headset does make a difference, (my friend’s Vive was particularly bad), but it’s not as great as you suggest. Time and practice are far more important.