Wafer prices have increased drastically in the last decade - to the point that midrange cards are no longer midrange priced.
It simply isn't really profitable to make real midrange cards anymore.
In addition, discrete GPUs market is a declining market and has been for 15 years or so. Therefore, in any declining market, the low-end and mid-range products will get squeezed and the high end will get pushed. The remaining buyers of discrete GPUs are willing to pay higher prices. Those who don't will buy a laptop with an Nvidia GPU already in it or some sort of SoC (like Apple Silicon/AMD APUs/Intel APUs).