It really hasn't been covered enough just how much Google has replaced organic search results with their own features. In some cases it's almost all of the above the fold real estate and for shopping they are starting to take over the checkout experience as well. It's significantly reducing organic traffic and turning e-commerce sites into Google suppliers.
It's been going on a long time, Google's been killing off aggregators by cannibalising their market for almost a decade now. I do wonder how sustainable it is, previously these aggregators did lots of things at Google's request, cleaning the noise out and laying everything out in nice data-annotations. More fool them, it turns out. Google cross-references them all, builds their 'own' data and drives them all out of b…
Amazon uses marketplace to access markets without risk or their own suppliers (making them a one stop shop in the process), then once they have the data, they start selling the stuff directly.
I worked in a music instrument retailer, when Amazon was aggressively trying to capture that industry, and they did start selling through Amazon, and if course Amazon now sells most stuff themselves now.
The problem as I see it is that these gradual monopolies pose huge risks to freedom and choice, as they lobby for themselves, and own bigger chunks of the world. Incentives change once you own entire markets, and it's naïve to think what started as a better experience for users will stay that way with less competition.
Not sure what can be done though. Antitrust stuff is really the last resort, and it's not a guarantee that it will even happen. In the EU it probably will I guess. USA not do sure.