My experience is the same as yours. It feels to me (similar to most LLM writing) like they write for someone who’s not going to read it or use it but is going to glance at it and judge the quality that way and assume it’s good.

Not to different from a lot of consulting reports, in fact, and pretty much of no value if if you’re actually trying to learn something.

Edit to add: even the name “deep research” to me feels like something defined to appeal to people who have never actually done or consumed research, sort of like the whole “phd level” thing.

"they write for someone who’s not going to read it" is a great way to phrase it.