I’ve seen this and I empathize. I’ve seen it lead to a sort of learned helplessness in developers who are supposed to own their whole stack.
I do think it’s unavoidable though. No company will have a truly open stack. There will be customized versions of everything, with caveats only the infrastructure team or developer-tools team are aware of. Naturally these teams become the go to folks to ask questions and resolve issues.
I don’t know if a good way around it. Documentation works to an extent. But at some point you have to decide what parts of the system you want to expose to developers, and whenever that happens you become the layer they communicate with rather than the underlying technology.