I'm not sure if both you and previous parent don't know, but the main useful thing with Recall is understanding whatever is on the screen, not just file accesses, or URLs visited but basically anything. So while Google's activity might see some parts, recent files sees another and so on, deriving that from screenshots captures everything you'd see on the screen.

I'm aware. You suggested querying local file access history based on their contents, that could be achieved without taking screenshots and OCRing them.