In big companies, the why is 80% of the work. I could swear actual dev work is less than 20% of a “developer’s” job at a standard large (non-SV/FAANG/tech-first) company. The rest is holding a lot of really weird organization-specific context in your head to make the right decision.
With my own tiny company, I used to answer questions about my code to support. Supporting the support. I remember doing that when working at big companies too.
Now, my support asks claude about the codebase to answer those sorts of questions. He's better than my memory.