FWIW my most recent car had a basic 400pp owner manual but a great deal was left out, with the owner referred to the online
manual for more detailed info.
My recent cars have also come with huge owner's manuals but the majority of the information covers the "infotainment" systems, other electronic do-dads and what all of the buttons and touch screen icons do. The other major topics were the nearly endless safety warnings and lawyer-speak and some maintenance guidelines such as oil and filter change intervals, etc. It had absolutely no repair information at all. That's what Youtube, books and past experience cover.