It's honestly hard to describe to someone who's never tried modern VR, but it basically gives you full immersion. You can watch Netflix in VR, you can move around (if you have enough real-life space), you can grab and play with things surrounding you, it's just so close to real life it's mind blowing. I actually wrote about social experiences (specifically playing boardgames in VR!) within the Go[1], and you can imagine that it has evolved exponentially with the Quest and the Quest 2.
I'm not sure how easy it is to get a demo, but look around you maybe malls or some arcade places will have a headset you can try. Or you can spend the $300 to get the Quest 2 :) It's honestly not that much to get a taste of the future.
It's definitely immersive, but after a while I found it wasn't any more fun than normal gaming, and the constant setup was horrible. I still can't look at a headset without wishing ill will upon the Oculus Home developers. Maybe I'll pick up another headset someday when I don't have to fix the play area every single time I use it and can put the headset on without thinking whomever designed it has a grudge against people with glasses.
In this particular case, it didn't have full tracking, you could only rotate your head (the 3dof mentioned in another comment). So even at launch it was behind the times. Full tracking is so much better, even required for VR to work.
Some of the latest stuff that's now possible is very small form factors, variable focus lenses, and correction for people who need glasses including people with astigmatisms.
