Modern GPUs like RTX 5080 are much faster for the applications that are limited by computational capabilities, mainly because they have more execution units, whose clock frequencies have also increased.

I suppose that most games are limited by computation, so they are indeed much faster on modern GPUs.

However, there are applications that are limited by memory throughput, not by computation, including AI inference and many scientific/technical computing applications.

For such applications, old GPUs with higher memory throughput are still faster.

This is why I am still using an old Radeon VII and a couple of other ancient AMD GPUs with high memory throughput.

Last year I have bought an Intel GPU, which is still slower than my old GPUs, but it at least had very good performance per dollar, competitive with that of the old GPUs, because it was very cheap, while the current AMD and especially NVIDIA GPUs have poor performance per dollar.