> but 14.3x perf.

Back then GPUs were designed to maximize gaming performance (no CUDA cores etc.). Now they are general purpose devices that can also be used for gaming. So it’s a bit of an apples to oranges comparison.

Rasterization performance seem to be only 3x higher (980 vs 5090):

https://www.videocardbenchmark.net/high_end_gpus.html

Of course you still get additional features like ray tracing, DLSS etc. which make the real gap much wider (but probably not 14x)