Companies that big should not be allowed to operate. They will have too much personal data and incredible unfair competitive advantage on the market. It's when capitalism doesn't work and where it needs to have emergency stops. Amazon needs to be split into independent companies. Now that Amazon will also know your medical history, know what you are talking about at home, all your preferences, who you meet, what are your problems, probably they know even more that Google. This should be stopped. We shouldn't be trading freedom for a notion of convenience.
However, in this case, the US healthcare system is so terrible and, in some respects, evil that I'm glad Amazon is working to disrupt (what'll probably end up being) large portions of it.
That's a problem right there that a small company couldn't challenge it. Healthcare also is in a desperate need of a reform, as currently is just a gravy train for fat cats meanwhile people are suffering and going bankrupt.
US healthcare is terrible because of system effects, not the profit motive. Most hospitals are run as non-profits and yet their spending is INSANELY out of control.
It all depends on your point of view. You can look at the scale and cry wolf, or you can wander about all the possibilities it creates.
If Amazon can listen to my breathing through Alexa, forecast an imminent health issue, and then Prime some pills to me before I even need them, that's a pretty awesome future.
We need to find a way to keep them from becoming evil and shipping me pain meds on subscription if I don't actually need them, sure, but technology has always been making the world better, and Amazon has the power to make it better on steroids.