The uplift in performance over the RTX 4000 is around 33% for the 90 series, and around half that for the 80 series, and less than 10% for the 70ti. According to leaks.
Therefore, unless people really need new "shiny thing". Then I don't think 4000 series GPU's are going to lose as much value as people think. Because the gains for actual frames per second are tiny compared to the 65% increase of the RTX 3080 vs the RTX 2080, are none existent, with the 4000 to 5000 jump, unless you get an RTX 5090 GPU, for around 2.5k? I predict FE models will be in short supply and AIB's will mark-up by £500.00...
Nvidia does it again. Poor value. Unless you crave those fake frames.
Why do you think the MSRP for the 70, 70ti and 80 cards are the same or less than the previous models? Answer, the performance is not there to exploit the consumer.