Quite a bit I think. Go module system did cover many use cases which Kubernetes cared but other systems may have not.

Kubernetes wasn’t an influencer. In fact go modules require semver and kubernetes doesn’t use semver. There are little things like that

Why Kubernetes in particular?

Because it’s huge, very abstract (pluggable components are a first class concept), very publicly-known (it’s name carries weight), and has numerous numerous active contributors, whose membership has evolved continuously over time. It makes use of a lot of magic to get over a lack of genetics, and has innovated in that case.

There aren’t a lot of other projects with that profile in Go. etcd and raft are similar, but are maybe an order of magnitude less “big”.

It's one of the largest open source ecosystems written in golang by lines of code, it's also a major priority for Google.

because the k8s project is full of generated code, which really hurts the readability.