Container orchestration is second nature to us SRE's, so it's easy to forget that the average dev probably only knows the syntax for deployments and one or two service manifests.

And pods, of course

A factor for sure, but as a programmer I find that the discoverability of stuff in code is much higher than with k8s.

Give me access to a repo full of YAML files and I'm truly and completely lost and wouldn't even know where to begin.

YAML is simply not the right tool for this job. Sure you got used to it but that's exactly the point: you had to get used to it. It was not intuitive and it did not come naturally to you.