A common spread I see in anti-trust discussion of tech (particular from outside tech) is the presumption that competition to Google look like Google, &competition to Facebook will look like Facebook - and people aren’t investing in search that means there is a ‘kill zone’

I’d suggest there are two problems with this. The first is that mature industries tend not to attract start-ups doing *exactly the same thing* - instead people come along and do something different. Okta or Twillio don’t compete directly with Microsoft, but they overlap.

The second is that the monopolist incumbent in a material lure tech sector generally doesn’t get overthrown by someone doing the same thing, but because the whole industry changes and makes that sector irrelevant

IBM’s mainframe business didn’t get overthrown, but mainframes stopped being the centre of the tech industry. Windows is still dominant in PC operating systems, but no one started a company to make Windows software in 20 years. No one is afraid of Microsoft or IBM anymore anymore

So part of the question - is your theory that Google or IBM are dominant in mainframes and search (correct), or that they have broader dominance in tech that stops companies from doing anything else?

This is the competitive dynamic in tech. you don’t overthrow the mature incumbent - you make it irrelevant https://www.ben-evans.com/benedictevans/2020/01/01/microsoft-monopoly-and-dominance