This explains it better than me
“ frame rate of a game constantly changes depending on the amount of processing going on: a less busy part of a game might run at a relatively consistent frame rate of, say, 50fps (although in reality this number will almost always fluctuate a bit), but a sudden explosion could see the console have to suddenly work much harder and the frame rate drop to 30fps or even lower. These constant and sudden changes in frame rate can cause stutter and tearing on displays that run at static refresh rates - which is pretty much all of them.
That’s where VRR comes in. A TV that supports VRR will dynamically match its refresh rate to the frame rate of the game, keeping pace with all of these changes. The result is smoother, more consistent gameplay.”
So it’s suppose to be better with VRR on but some of us have seen flickering. But could have been the game coding as well. I have also read some place to keep ot off. Ha ha, now we are all confused again.