For what you do and have invested, it probably isn't worth jumping ship.... at this stage. However the D850 does beat the **** out the 5DIV
However, if Canon carry on the way they are with mediocre upgrades like the 5D IV and hold back features so not to tread on their other products, show no innovation but at the same time charge over the top prices for it then it's not going to be long before you have to question it. If I was a Canon shooter now I would have jumped to Sony probably so I could still use the lenses.
I think both Nikon and Canon have been stuck in their ways for a while but on this you can see that Nikon has thrown everything at it. Even the focus stacking which apparently was due to their engineers liking the super macro shots they'd seen and thought it would be cool to put in the camera, it's things like that we want to see and actually that is one thing I'm looking forward to trying out.