VR is immersive, but it’s hard to fit in to life and there’s a limited array of content available. You can easily use a computer, watch TV or play video games while still being somewhat present with the people around you in reality. VR makes that impossible: you cannot see them, and they cannot see what you see (so even the experience of watching someone play is gone). Furthermore, this makes the experience hard to share — sharing it requires doing that as a whole activity, an activity which only one person can participate in.

Compare with setting up a home theater and having people over to watch a movie, or split screen gaming.

After all that you run into the limited content availability and, as you noted, the high price.

I do wonder why Meta hasn’t done something like license Skyrim or GTA for the quest. It shouldn’t be too expensive compared with the other investments, and would bring over some solidly popular (and big!) content.

Regarding the last point, unfortunately most games can't really be ported to VR, they need to be specifically developed for it.