This is a pretty narrow view. Most APIs out there are not source available, frontend libraries are the odd one out in that regard. Likewise for docs, it doesn't matter if the LLM can read the docs or not if the docs literally don't include the things you need to figure out. I suspect this is a generational divide, people who grew up with SO can't imagine what life was like before it, but right now we're on a straight course back to isolationist communities, if we aren't already there.