Seems arbitrary to assign all the RTX "high end", if you're not going to assign all the GTX "low end".
Using nVidia's marketing distinction, it's a binary division into two groups (GTX, RTX). Logic says you could call RTX Tier1 and GTX Tier2 if you wanted.
But your logic says RTX is Tier1, and GTX is a mixture of Tier 2 and Tier 3 (analogous for "high end", "mid range", "low end").
It very much seems to me that the whole thing is subjective, as opposed to there being some concrete criteria that makes a 2060 unquestionably "high end".
After all, I could legitimately ask the question, "Why can't RTX be a mixture of Tier 1 and Tier 2, with all GTX being Tier 3?"
This isn't argument for argument sake, I'm just trying to establish the highly subjective nature of calling something "high end" or not, using simple logic.
I could you ask the same question, why are you calling the xx70 and xx60 mid low and mid range?
I was just keeping my answer simple, but, I forgot how you like to twist things.
The point I was making is that just because a card has xx60 in it, doesn't mean it's mid low anymore. It also depends on whether it's RTX or GTX. It's sort of like back in the days of 9 series cards and below. Where you could have the 8800 GTX, the 8800 GT, 8800 GS but you also had the 8600 GT and the 8600 GS etc. The GT and GTX signify the differences in performance as well as the numbers.
Rather than look at the internal naming scheme, try looking at the die sizes. They are more of a clue to where the card is going to be in a line up then the internal naming scheme. For example, the 1080ti die size was 447nm on a 14nm process. The 1060 is 200nm. Now look at latest cards from Nvidia. The 2060 is 445nm and 1660 cards are 284nm.
And don't forget to include hardware features, like the Ray Tracing and Tensor cores. Which the mainstream cards do not have.
Simple logic.