The lesson of lens convenience over quality became as lost as the Dead Sea Scrolls until about 15 years ago, when zoom lens designers were at last able to try ideas they had been championing unsuccessfully for years. Could they get away with creating variable-aperture zooms that could start with a large opening at wide-angle but would have a smaller aperture at maximum focal length? Zoom lens size, weight, and cost could be reduced dramatically. Lens makers tried it. Would buyers accept it? They did. For instance, instead of a zoom having a maximum aperture of f/2.8 throughout the focal length range, it could start at f/2.8 and gradually shrink to f/5.6 or so.
And so this was done. And it is precisely these lenses that are now sold so successfully to us.