> From my specific perspective in IT, the increasing centralization across every vendor category (three major x86 server manufacturers, two CPU vendors, two GPU makers, three global-scale public clouds, ISP mono- and duopolies, a handful of commercial operating systems, a near-monopoly EUVL supplier - the list goes on) is a dire threat to not just the open internet, but open technology in general.
Part of the reason why we have seen this absurd centralization is complexity. It used to be possible for third parties to tape out an x86-compatible CPU and in fact there were multiple vendors doing this - but it's impossible these days, mostly from a financial viewpoint (you'll probably need a few billion dollars in R&D plus the licensing cost), but also from a technological viewpoint - you'd need to have feature parity with Intel/AMD x86 CPUs and some material improvement actually enticing people to buy your new CPU.
In the end the "free market" will always lead to such concentration effects and, most importantly, to de facto standards because the dominant actor(s) will always be the cross-section of "offers the most features, is used everywhere else, is affordable".
The fix requires governmental intervention (be it anti-trust legislation, mandatory sharing of resources/access for dominant entities or whatever), but sadly we can't even do regime changes to get rid of kleptocrats like the Taliban any more...