Performance wise there isn't a huge difference but if you are using those extra features at this stage the difference is night and day, so while at launch there wasn't a big difference but with things like DLSS 2.0 which is going to become quite a common thing you have plenty of cases where the 2060 outpaces the 1080TI while looking better. nVidia had to get the tech out somehow and they couldn't take a loss on it so yeah early adopters foot the bill as always but now that it is here it is going to dominate.2080ti = Titan with RT Cores
2080 = 1080Ti with RT Cores
And so on. They was no real performance difference between the generations, overall, just added a at the time unused feature, relabeled the products and charged more for them.
However, the 5700 and 5700 XT is faster than the previous Vega 56 and Vega 64, uses significantly less power and costs less at MSRP then the Vega's, as well.