I agree with a lot of the "Greedy nVidia/AMD" and "Idiots keep paying it" sentiment in this thread, along with the cryptocurrency mining inflation issues we saw: but I'll also note that graphics cards stay relevant a lot longer nowadays
10 years ago you had to upgrade your card almost every year to stay current - as Diagro points out, he used to be able to afford a top end card every year... but you felt like you had to buy a top end card every year. Even things like the 8800GT got out of date surprisingly fast. Whereas nowadays, you can run a card a lot longer: I'm on a 2-year-old 1080 (a card that was already a year or so old before I got one) and am yet to find a game that it's uncomfortable with: and I only upgraded it from the previous 1070 because that card died
I'll also note that fewer people seem to buy mid range GPUs - a few years ago cards like the GTX 260/460/660 were all very popular, whereas you don't see as many 1060/1660 (non-ti) versions around.
When kit lasts longer, people are happier to pay a bit more for it. Although I'll admit the current prices are getting a bit silly - a mid range GPU nowadays starts at £200-300 - my 460 cost £125, my HD7770 was £100, my brother's HD7870 and my GTX960 were both £150, my 970 was £200.. that all seems pretty sensible, then suddenly things shot up.