With a normal display you get sample and hold motion blur from fast motion.
If you look at this https://www.testufo.com/framerates-versus there is text over each of those characters and you can't really read it as it scrolls by. If you had BFI you would be able to easily read the text.
When your display is showing something moving it's showing it in one spot, then it nearly instantly teleports to the next spot. Your eyes and brain add blur to this unnatural movement. BFI solves this by flashing each frame then just showing black inbetween, your eyes and brain naturally handle this and everything is clear.
For whatever reasons very few displays have BFI and almost none have simultaneous BFI VRR.
If you don't have VRR you need to maintain a constant 120 FPS to get smooth motion and have BFI work well, which isn't really possible unless you're playing an old game or on low settings. That's not really worth it to me so I always choose VRR. If BFI worked with VRR you could get the best of both worlds.
You've got better vision that I do. I play satisfactory at 90-120fps and its smooth as butter to me.