Not really. You are referring to a privatisation, where most of its problems came from a lack of legal and regulatory framework. Germany, France and Spain have the train operator detached from the infrastructure/network, and they have the most developed rail networks in the world. But again, this is not the case. The telecom case is a rollup of assets into a NetworkCo, making all telecoms MVOs.
‘detached’ as in ‘different parts of the same company’ in Germany and a rather pro-SNCF entity in France. While this is generally a good idea, especially if you combine it with standard tickets s.t. you only need to buy one ticket even if you use multiple train operators on your route (cf. National Rail in the UK)[0], it is certainly not the reason France or Germany have the ‘most developred rail networks’: the reason for that is showing off to their neighbours, even if it sometimes doesn’t make much sense :)
[0] This only works in state-subsidised short-distance trains, long-distance trains not operated by Deutsche Bahn need different tickets, I believe the same goes for France.
Unfortunately you are mixing concepts and analogies. By detached I mean two independent companies, like I mention on the original comment. The rail-network analogy is not comparable to what I refer too. The energy sector analogy is a like-for-like example to the current telecom concept, again, like I mention in my original comment.
We did that in the UK with our train network. It isn't working out so well.