The Google Docs commenting tool is an affordance for nitpicking.

Challenge yourself to give high level responses in a separate email or channel.

That forces you to not talk about object-level details and nitpick but instead give high-level feedback about the whole.

If there are multiple comments that are multiple paragraphs, that's a good sign the doc author and the commenter should just have a live conversation about the high level questions and get out of the details.