[Discussion] How to read? Deep or Quick?

I was ghosted by a writer after spending many many hours beta reading and commenting on a story. I'll never know why, I guess.

There were some factual issues that I pointed out based on my expertise. I think that's fair.

I wrote up a more big picture document. It had a pretty clear DNF turn for me. I think that's fair too, since it's a reader experience thing the author needs to know. (I did keep reading, though)

As a writer, I know I have blind spots, so I feel queasy about responding only to questions the author asks. I wouls ask about my known weaknesses because I'm working on them, but a reader might find a major flaw in the premise or a character's development, which I would want to know.

Should a beta reader just read through more casually than I did and just give general comments?

For a better experience in the future, what advice do the more experienced readers here have to offer?