I think Kubernetes in principle gets a lot of things very right - but it has over time grown into this huge amorphous blob of complexity that makes it very easy to shoot yourself in the foot with, as many people said :)

That issue is not endemic to Kubernetes, but rather to any larger system past a certain age, you learn stuff as you go along and would do stuff differently if you did it again today - but you can't easily, because you cannot break compatibility for everybody using your stuff.

As a concrete example from the Kubernetes world, there is a talk by Tim Hockin [1] about how today, they would fundamentally design the api-server differently and base pretty much everything on CRDs.

[1] https://www.youtube.com/watch?v=ji0FWzFwNhA