That is absolutely the end goal of all these network-effect companies. Uber wants to be a monopoly on transportation, Google a monopoly on search, Spotify a monopoly on music consumption, etc.
Monopoly is if one corporation owns an entire market. This is about multiple corporations. The proper word is cartel or "corpocracy" which dislike as corporations are just a legal fiction. Someone still owns the corporation. The article isn't really about americans not owning stuff. It is about average americans not owning stuff. Poor, or at least not-rich, people are today less likely to own things like houses and cars. But the rich still own plenty. They are owning a greater percentage of everything. So perhaps the best word is plutocracy.
> Monopoly is if one corporation owns an entire market.
This isn't quite right. Traditionally for a company to be a monopoly it isn't even required it control a majority of the market. It has more to do with the company being in a privileged circumstance in a market and explicitly using that privilege to bolster themselves or suppress competition in the same or related markets.
An example is Microsoft with Netscape. Microsoft was sued with anti-trust laws not because IE or Windows owned the entire market, but because Windows gave Microsoft a privileged place in the web-browser market that they abused.
It does, partially. While it's no replacement for democracy or other forms of cooperative stakeholding, the one avenue we have for influencing companies we grow to depend on is through our business. Monopolies remove that sole piece of leverage.