On your first point: I seem to remember plenty of companies that failed that were not telecom. In fact when I went looking just now I found a bunch of listicles about retail startups that failed.
The telecom bubble and crash was almost a side-effect. The telco executives saw the web taking off and used it to justify wildly over-inflated projections of traffic demand growth, and then began building out debt-financed networks to meet it. When the traffic didn't materialize (partly because the dotcom bubble burst), they had a bunch of overcapacity not generating revenue to service the debt that financed it, and that killed them.
The telecom bubble and crash was almost a side-effect. The telco executives saw the web taking off and used it to justify wildly over-inflated projections of traffic demand growth, and then began building out debt-financed networks to meet it. When the traffic didn't materialize (partly because the dotcom bubble burst), they had a bunch of overcapacity not generating revenue to service the debt that financed it, and that killed them.