Looking at the numbers from ComputerBase, I became kind of curious about how Ampere fits in on a historical context. Especially with all the discussion about whether the 3080 should be considered part of the XX80 class of cards or the XX80 Ti class.
So I plotted the historical cumulative performance/$ gain for each generation using the 700 series as the baseline, and included a trendline for the 700->900->10 series (the number for the 3070 is based on an estimate of the 3080 being 30% faster than the 3070):
Based on this it is clear that the 3080 provides a perf/$ improvement that is roughly comparable to that of the 900 and 10 series regardless of whether you consider it part of the XX80 class or the XX80 Ti class, but not big enough to make up for the very subpar improvements of the 20 series.
The 3070 provides an improvement that is almost good enough to make up for the 20 series within the XX80 class. I didn't plot it within the XX70 class, since Computerbase didn't provide those number, but I suspect it would look worse there.
The 3090 meanwhile is clearly below historical standards for the XX80 Ti class (same as the 2080 Ti), but I suspect it would look better if you compared it to Titan cards.