That goes for every amount of wealth. Poor people probably relied on their extended networks since the beginning of time. (From that perspective, urban social individualism and reduced social dependence are a lifestyle enabled by modern abundance.)

I think he framed it that way to gain relevance. It is a common gesture to indirectly refer to a previous time without any historical substance. Especially in politics and social science.

If we assume it's a rhetorical gesture, "the influence of networks increased" is just "i think networks are important". Saying the latter is legit, I guess.

Same for wealth concentration. Compared with 1700, we live in an egalitarian garden eden. ..however, "the increasing gap between rich and poor" is a useful gesture to say "I think considering the gap between rich and poor is important". - Which again, seems legit to me.

I think the author is referring to increasingly distributed networks as opposed to the more centralized legacy networks. So electric networks vs. Paper based networks.