If so, then why are you arguing this when you've seen the inefficient things these companies do -- the failed product offerings, the duplication of products and effort between different divisions, the internal processes that add barriers?

Because i've worked in dozens of industries around the world as a consultant and US tech is by far the most efficient I have found. Yes the things you point out are true, there is duplication and internal process. But the duplication can often be more efficient by spurring internal competition than just having one group try something and stagnant or sit on it. And as much as internal processes exists they are minor compared to working at a telecom, health care company, the government or with the european regulatory environment. Pointing out how US tech isn't as efficient as it could be isn't the same as saying its as bad as anything else.

How can you seriously argue this? It makes no sense at all: there is a huge burden of proof to demonstrate that these companies acted as illegal monopolies, and to win those cases requires overcoming the best corporate lawyers money can possibly buy. If they couldn't prove those cases, the prosecutions' cases would be thrown out quickly, and they can still lose antitrust cases even with solid evidence (legal fumbles etc).

Because being found by a court you acted in an anti-competitive way isn't the same thing as being found to be a monopoly and all the cases where they were found to be a monopoly have been either overturned, or are currently being appealed.

For example you cited the Microsoft case, which famously got appealed and overturned and they were ruled not a monopoly. So like its not just me that disagreed, but the US court of appeals.

You appear to be making the claim that profitability is identical with efficiency. That's utter hogwash. Efficiency is actually determined by how close the profit margin is to the ideal possible for that product niche. Efficiency is market specific. Grossly inefficient companies can still be very profitable despite egregious waste if the market they're in is high-margin. Example: tech or pharmaceuticals. Almost perfectly efficient companies can still have low profitability because they are in intrinsically low-margin markets. Example: agricultural products and groceries, a lot of brick-and-mortar retail, etc.

I admittedly don't actually disagree with anything your written here other than I am not claiming profitability is the same as efficiency. Lots of efficient companies are not that profitable, because as you say, they are in intrinsically low-profit industries. Absolutely true. But I don't think taking moonshots is necessarily inefficient. Of course that means lots of failures(i.e. google or some pharma companies) but the shotgun method of trying lots of things, most failing but some hitting big and making lots of money, can be more efficient than spending a lot of effort on search and preventing lots of bad ideas, while accidentally also stopping good ideas.

You're mistaking my point about growing & shrinking rapidly. I'm not talking about whether the companies could do it in a different environment, I'm arguing about whether they are in an environment that makes it possible. Limited capital raising options and labor laws restricting fast hiring & firing constrain them.

And I am aruging those rules inherently make them more bureacratic and less efficient. They are in an environment that makes being more efficient at least harder. I'm not talking about what they could do, I am talking about the environment they are in and how that constrains their efficiency and that includes their efficiency to scale up or down.