38 karma · joined March 20, 2021
For the rest - yeah, f# is just one of important specifications.
https://gs.statcounter.com/vendor-market-share/mobile/belaru...
https://en.wikipedia.org/wiki/Sergey_Prokudin-Gorsky#Gallery
He took 3 photos with different colour filters in succession and captured them on large glass plates. Naive alignment possible before digital technology limited the quality of results, but as original separate negatives survived - it was possible to scan them at high quality and properly align digitally. So now we can see those photos in true colour and high quality.
As one of examples a very vivid photo of Emir of Bukhara taken in 1911:
https://upload.wikimedia.org/wikipedia/commons/3/33/Prokudin...
As for the time between adoption and enforcement - there has to be reasonable time given between for everybody to adjust to the new regulation.
Technological replacement happens when new tech has important advantages over the old, without needing to outperform it in every single way.
The main reason for the improvements in quality - closer (and for some - larger as well) mount allows more freedom for lens designs, leading to previously impossible approaches. Another change - with photographer never seeing a direct image from lens (only a processed one via EVF or back LCD) - the abberations that can be easily corrected in post can remain less corrected by lens design, allowing better correction of other parameters within the same constraints.