From "Pedalare! Pedalare!" by John Foot, which I was re-reading last night, pp236-237:
"By the 1970s, then, cycling had changed dramatically from the golden age of Coppi, Bartali and Magni. Cyclists were fitter, equipment was better, the roads had been vastly improved, teams were organised in a businesslike way, doping was more effective (and becoming more scientific) and there was far more money around. Racing was, as a result, much faster and much more predictable. One of the results of these changes...was that cycling became more boring. There were fewer breakaways, fewer heroic solo rides, fewer falls...
Technology mattered as well. Equipment failure became less significant, the weather counted for much less and new types of riders emerged - all-rounders and pure sprinters, specialists who no longer needed to ride the Stelvio on their own for hours in order to win or become rich. Time trials were more and more central to overall victory. The days of un uomo solo e al commando were gone, more or less for ever...Increasingly, the peleton <sic>/gruppo became hegemonic over the efforts of individuals, as all the riders became faster, and team organisation much more scientific. Improvements to the sport and its participants thus destroyed much of it fascination. An intrinsically individual sport became imprisoned by the power of the collective."
So there you have it...