Is this not a bit "tail wagging the dog" thinking? There wasn't much innovation in telecommunications once Bell's monopoly was entrenched. Once it dissipated, innovation was everywhere in the space. Similarly, computers had less innovation while IBM was a monopoly than they've had since its monopoly dissipated.
Though both companies created novel & useful inventions, the biggest shifts in those industries during those monopoly eras were from outside those organisations by competitive startups. As an example, IBM should have produced Microsoft, but they didn't. They missed out on a multi-trillion dollar value creation opportunity as a result.
There's a difference between conducting basic research and bringing new inventions to the market in the form of consumer goods or services. Monopolies are much, much worse at doing the latter than normal businesses because they have no competition pressuring them to improve their offerings.
> There wasn't much innovation in telecommunications once Bell's monopoly was entrenched. Once it dissipated, innovation was everywhere in the space.
I don't think that's accurate at all. If we take say 1920 or so as the date when the monopoly was entrenched and 1984 as the break-up, there was tons of innovation in telecom in that time period. Novel telecom technologies introduced in that time period include television, microwave relays, satellite communications, submarine telephone cables, cellular telephones, fiber optics, electronic telephone switching, packet switching, the Internet.