The danger with government nationalizing telecommunications networks is that once it is done, innovation and quality go way down. We had nationalized telecommunications for over 70 years and customers could only have one brand of phone, and we're limited in the number of phones available in their houses. In addition, long distance calling was cost-prohibitive. The monopoly only started cracking when MCI introduced mi…
AT&T also provided an extremely high quality of service, not really seen since that time, and operated a corporate R&D arm that I think could fairly be called the global center of innovation for decades, designing as an almost side-effect of telephone switches a large portion of the computer technology we use today from silicon to operating system. One wonders where the state of the industry would be today had Bell L…
for a monopolist to offer high quality products and service is exactly part of the monopolist's playbook, not any sort of consumer benefit. The overly generous profits they earn allow them to use comparatively smaller quality enhancements as a barrier to entry for competition. The point is that "high quality service that you pay too much for" reduces the overall level of consumption. So, while the smaller market is happy with the service they receive, a larger market is receiving less service than they want because the price is artificially too high.
Monopolists absolutely do restrict supply, and economists all agree that monopolists are bad for markets.
The part where you suggest "particular situations" is essentially reflective of the other monopolist tactic of "bundling", product mixes designed to price discriminate separate market segments, again, always to the monopolists benefit.
The theory of monopoly is quite robust, and your arguments in favor of the benefits of monopoly do not hold any water whatsoever.