It doesn’t invalidate it. It’s accurate that for a time, privately owned, for-profit newspapers would (and did in the past) result in a multitude of viewpoints since the editorial stances will are inherently more diverse between 20 newspapers instead of 2.

Whether or not the current vertical and horizontally integrated media companies will be broken up is irrelevant to the fact that it would result in a more diverse and freer press.

A tax funded solution would most likely take the form of a single entity. If 4 entities dominating the press is wrong, then 1 is even worse.