I generally agree with you, but I'd be interested to hear your take on what the purpose of CI _actually is_.

It seems to me that a big part of the problem here (which I have also seen/experienced) is that there's no one specific thing that something like GitHub Actions is uniquely suited for. Instead, people want "a bunch of stuff to happen" when somebody pushes a commit, and they imagine that the best way to trigger all of that is to have an incredibly complex - and also bespoke - system on the other end that does all of it.

It's like we learned the importance of modularity in the the realm of software design, but never applied what we learned to the tools that we work with.