It doesn't help that GPUs have also generally gone up over the past decade because there's more market for them besides gaming, along with how they benefit from being hugely parallel and the larger you can make them the better, and fabrication costs are shooting up. I think there was a GamersNexus video at the launch of one of the previous GPU generations that noted that there was a move from "more for your money" each generation towards "more for more", i.e. keeping the value roughly static and increasing the amount they charged for a more capable product.