Some photographers are better than others. Some cameras and lenses are better than others. Why are some people apparently unable to separate these two simple, non-contradictory statements?
Point out that any given lens is (for example) not very sharp, lacks contrast or suffers from field curvature, and immediately, someone pops up and says, "Yeah, but you can still take great pictures with it."
OF COURSE YOU CAN. Only a fool would deny it. You may even be able to turn these defects to advantage, despite the fact that from the point of view of lens design, they are unquestionably defects. But equally, there will be other pictures, other subjects, other ways of seeing, which will work better with a lens that is sharper or contrastier or otherwise technically better. Again, only a fool would deny it.
Any lens is a compromise on speed, optical quality, size, ergonomics and price. My 50mm C-Sonnar, for example, sacrifices quite a lot to size and contrast; my pre-aspheric 35mm Summilux sacrifices a good deal to speed and size. They're both fine lenses. The compromises they make suit me. But I don't pretend that they are in all ways comparable with the latest Leica aspherics in the same focal lengths. They're smaller and cheaper for a start.
Still less can anyone pretend that a lens from 60 years ago is likely to compare with the best of today's lenses when it comes to technical quality. A few do compare well: 21mm Biogons spring to mind. But most don't. You may love them; you may take great pictures with them, or admire the great pictures that others have taken with them. But you can't realistically deny that technically, most high-end modern lenses are superior to most high-end old ones -- especially when it comes to fast lenses or wide angles.
Whether or not the photographer needs, or can take advantage of, better cameras or lenses, is a separate issue. That's down to the photographer, not the camera or lens. But to deny that some cameras and lenses are better than others is as feeble-minded as denying that some photographers are better than others.
Cheers,
R.