Because the concept of skills is not tied to code development :) Of course if that's what you're talking about, you are already very close to the "interface" that skills are presented in, and they are obvious (and perhaps not so useful)

But think of your dad or grandma using a generic agent, and simply selecting that they want to have certain skills available to it. Don't even think of it as a chat interface. This is just some option that they set in their phone assistant app. Or, rather, it may be that they actually selected "Determine the best skills based on context", and the assistant has "skill packs" which it periodically determines it needs to enable based on key moments in the conversation or latest interactions.

These are all workarounds for the problems of learning, memory...and, ultimately, limited context. But they for sure will be extremely useful.