It didn't matter that TnL had no games because the GPU had a nice generational bump in performance.
However, RTX didn't have a bump in performance. It basically matched Pascal.
1. You are changing the goal posts, basing a new feature like RTX based on support or results
2. As for the pascal comment LOL, 20-30% boost in rasterization performance, reworked SM's and RTX on a not much smaller process (remember AMD only just match Pascals performance per watt with a 'new' architecture and process half he size), rasterization jump is is impressive considering the lack of proper new node but not as impressive as Kepler to Maxwell.
3. You are not addressing the pixel shader side of what I said as you prob well know Pixel shaders did reduce performance a lot in the early days.
4. As for the TnL comment, back when TnL was new chips where smaller and had less power draw do designers could aforder to brute force performance jump from
Fahrenheit to
Celsius architectures by doubling the number the pixel and texture pipelines etc. TLDR, die space and power was less of an issue 15-20 years ago. Turing does offer a jump in rasterization performance, reason why Turning and RTX gets as much stick is the price of the cards (and righlty so in that regard) but nVidia can get away with it as AMD has been absent from the high end almost 4 and a half years.
Im RELAY looking forward 2020, intel Xe on the since new 7nm cards from nvidia
Maybe this mythical "big Navi" might show up too up i subset it would drop not long before or after nvidia's new card but offer "3080" performance at best. Going by the performance and the powerdraw of current 7nm Navi, this is educated guess on my part though.