You're right that we should all have some skepticism of centralized power, whether it's the government or somebody in the private sector. You and I agree on that.
I think the last couple of sentences of your post is where we mostly disagree. People like me look at Amazon as a company that essentially solved a massive logistics problem, changing the world greatly for the better. The average person has a measurably higher living standard thanks to Amazon, significantly so in many cases. The "victims" of Amazon are mostly other businesses, but Amazon itself generates substantial benefits for consumers as well as its stockholders. That's the sort of thing that we should generally celebrate. If firms are going to succeed and generate a boatload of profit for their owners, we should want them to be firms that produce value for consumers too. Nobody seriously disputes that Amazon fits that profile. So people like me put more weight on the "benefit" side of the ledger than you do.
On the "risk" side, what's the risk? That Amazon will somehow monopolize retail industries? People were making literally the exact same argument about Wal-Mart 20 years ago, and then Amazon came along and started eating their lunch. Big, network-intensive firms like Amazon have some clear competitive advantages in terms of economies of scale and scope, but they're not invincible and they can be overtaken if somebody offers consumers something better. So the other difference is that people like me worry less about the "risk" side.
Probably a more succinct way to put it is that much of what a person might do to mitigate the risk of Amazon is going to do more harm to consumers than good, at least in my view.
I'm not sure we disagree on the benefit side of the ledger really. We may disagree a little bit around how ethically they got as big as they are, and their practices in undercutting competition. But I think the main area of disagreement seems to be how significant the risks of a company the size and breadth of Amazon are..
A core free market principle is competition and choice. Amazon is shutting down competition on a far larger scale than the Walmarts of the world. Amazon hosts through its AWS platform a third of the internet (roughly). They're partnering with the federal government and local governments on incredibly huge data hosting and analytics projects. They gather unbelievable amounts of data on customers, and are continually expanding ways to use data to drive behavior to sell more products and grow larger.
It's my view that there will come a time very soon, if we're not there already, where a handful of companies like the ones listed here, will have unrivaled access to consumer data, to demographic information, and will be experts in using the data to drive and control human behavior in ways we've never seen before. Google, Facebook, and Amazon come to mind in this conversation. With the improvements being made to AI, to analytics, and increasing amounts of information being transmitted, stored, and analyzed by a small handful of companies, the ability for other companies to come in and disrupt this marketplace becomes almost impossible.
So to attempt to be more concise, I think the risks are vastly underrated that these companies pose by controlling information and distribution in the modern age. They have their fingers in the pulse of the digital economy, have near monopolies on data, and they're cutting out competitors. While we may be experiencing some conveniences now due to efficiencies they offer, they're rapidly grabbing all the available oxygen in the room in a way that new entrants will find it impossible to breath unless they wear a "big company" branded oxygen mask and play their game.
The era we're entering is one of data and digital monopolies, and the world is generally only prepared to worry about the older types of monopolies. So right now, so long as stock prices are increasing, market caps are growing, everyone seems happy. But to me, those who hold conservative views especially about the risks of centralization of power in government, should be increasingly worried about that happening in the business world.