and when the solutions did come they were burdoned by kludges necessary so as not to break backwards compatibility - and especially not to complicate life for the killer app of the platform at the non-gaming level, the video toaster, which was very tightly integrated with the Amigas interlaced video system.
ECS could do non-interlaced 640x480 (+overscan) with 4 colors. In the documentation, 35 nanosecond pixels.
AGA same, but with 256 (or 262144 HAM) colors.
I think Commodore made one monitor that supported a bi-modal scan rate, and it was something like twice as expensive as the the regular Amiga monitor range. I also recall a somewhat exotic NEC 17" flat-face CRT monitor that was completely out of the question pricewise for almost anybody except institutions, that also could do it by virtue of having a continuously variable sync clock from 15 khz up to 45 or so.
The problem is not VGA 31 kHz modes, but old 15 kHz ones.
Most Amiga modes are 15 khz. The average person with an A500 or A1200 would have a 1084S and get zero value out of the new modes.