Has anyone else noticed that inexperienced founders are poor at documentation?

My experience is from meeting a couple people on YC cofounder matching/online, who are looking for a dev (me) to join their b2b idea. We talk, they have an idea, and talked to a few or couple potential customers, but can't produce any recordings or transcripts of their conversations. Or a document summarizing their findings and the market research. I'm immediately disinterested at how little information they can produce. They just tell me the idea over a call as if I'm going to remember everything, and as if they remember every insight from those conversations. I'm in a b2b startup rn, and I record every customer call, and note down interesting snippets/emails in a doc. When I look back at recordings, I realize that there are many nuggets that I didn't remember. And that's even with a good memory. I'm still pre-mvp with a waitlist, so wondering what more experienced founders think?