> you wonder whether capitalism truly does produce the most efficient allocation of resources

it does, but current state of capitalism has kinda degenerated. the main sentinel about this is the fact that us antitrust has not imposed any decent spinoff in the last 20-25 years.

just to give you an example of proper activity of antitrust activity: IBM released the ibm pc as a farily open/standard platform in the 80ies because it had just got out of a multi-year, very serious and very expensive litigation with the DoJ.

The litigation lasted 13 (!!!) years, from 1969 to 1982. See https://truthonthemarket.com/2020/02/03/the-ghosts-of-antitr... if you want to know more.

Think of what the DoJ should do to Amazon, Apple, Google and Microsoft (which had its own antitrust lawsuit... in the 90ies).

I don’t think that’s true at all. IBM was forced to be fairly open/standard because that was the only way to quickly enter a rapidly growing and changing segment. They tried to drag it to proprietary with their follow-on PS2 and only cratered their business, all without antitrust intervention.