No, we didn't.
980 -> 1080: 51% perf increase for 9% more money (38% FPS/$ increase)
1080 -> 2080: 39% perf increase for 17% more money (19%)
2080 -> 3080: 63% perf increase for same money (63%)
3080 -> 4080S: 49% perf increase for 43% more money (4%)
(TPU figures, USD MSRPs)
Yes, the 4080 looks crap but only because of the 3080 which offered a big boost but at an MSRP that was virtually unachievable.
If we change the MSRP of the 3080 from $699 to $849, which is a far more realistic value, then it looks like this:
980 -> 1080: 51% perf increase for 9% more money (38% FPS/$ increase)
1080 -> 2080: 39% perf increase for 17% more money (19%)
2080 -> 3080: 63% perf increase for 21% more money (35%)
3080 -> 4080S: 49% perf increase for 18% more money (26%)
Basically it's the 3080 that makes the 4080 look crap because it was too good/cheap.
You can see the same thing with the 1080Ti, a card that was also too good:
1080Ti -> 2080Ti: 31% perf increase for 43% more money (8% FPS/$ reduction)