Having built AI summary interfaces for clients, I can say this stuff is not as simplistic as people think. And only the most simplistic analysis could conclude that a summary is equivalent to a full treatment.

A document might serve many audiences, some of whom want more or less detail. Sometimes the summary is enough but you want the detail there in case you want to dive in on some aspect or another.

Maybe you want the summary to know if it's worth reading in full.

And summaries are not one-size-fits-all. When I ask AI to summarize something, I ask it to pull out specific things I care about. You might summarize it differently because you care about other things.

A summary is a lens. It distorts. It also magnifies. Lensed views are useful, but they are not the original.