I doubt policymakers in the early 1900s could have predicted the impact of technology and globalization on the corporate landscape, especially vis a vis “vertical integration”.

Personally, I think vertical integration is a pretty big blind spot in laws and policies that are meant to ensure that consumers are not negatively impacted by anticompetitive corporate practices. Sure, “competition” may exist, but the market activity often shifts meaningfully in a direction that is harmful consumers once the biggest players swallow another piece of the supply chain (or product concept), and not just their competitors.

Not really. It's a network effect, like Facebook. Value scales quadratically with the number of users, because nobody wants to "have to check two apps".

We should buy out monopolies like the Chinese government does. If you corner the market, then you get a little payout and a "You beat capitalism! Play again?" prize. Other companies can still compete but the customers will get a nice state-funded high-quality option forever.