So... Four years? The 1080 launched in 2016, and the 3070 launched in 2020, for $100 cheaper — the launch price of the 1080 was $699, and the 3070 was $599. The 3070 easily trounced the 1080 in benchmarks.
The 3060 effectively matched a 1080 at $329 in 2021 (and has 50% more VRAM at 12GB instead of the 1080's 8GB), so call it five years if the 3070 isn't mid-range enough.
The 3060 Ti launched in 2022 at $399 and handily beat the 1080 on benchmarks, so call it six years if you want the midrange card to beat (not just match) the previous top-of-the-line card, and if a *70 card doesn't count as midrange enough. Less than a decade still seems like a reasonable claim for a midrange card to beat a top-of-the-line card.
The 3060 was only readily available quite recently, so it's about 6 years from ready availability of the 1080 at $600 to 3060.
Taking 6 years to double the perf/$ implies that it would take ~42 years for a $40000 H100 to reach mid-range levels. Assuming scaling, particularly VRAM, holds.
And plus it would be getting really close to the Landauer limit by that point.
The 3060 effectively matched a 1080 at $329 in 2021 (and has 50% more VRAM at 12GB instead of the 1080's 8GB), so call it five years if the 3070 isn't mid-range enough.
The 3060 Ti launched in 2022 at $399 and handily beat the 1080 on benchmarks, so call it six years if you want the midrange card to beat (not just match) the previous top-of-the-line card, and if a *70 card doesn't count as midrange enough. Less than a decade still seems like a reasonable claim for a midrange card to beat a top-of-the-line card.