Yep, it appears that the deepest format we have today is long-form hypertext. Often containing a few 10min videos itself.
Some people do equate those with books, but it's far from unanimous.
Lots of surface level books that are the length of a book and the value of a 5min tiktok too.
For anyone who wants to get back into reading books my advice is to start with whatever sounds fun. A lot of people fall into a trap of feeling like they need to read something useful or serious and just get turned off to the idea. But reading lighter books are still great and provide a lot that you won't get from tv and similar mediums. Over time your interests will evolve naturally into new areas.
Modern 8 to 10 episode series can get close to being as nuanced as a good book. You simply need space to go deep, no amount of cleverness will help you do that in a short format.
The modern stuff feels like total fluff compared to a book, which in turn feel like total fluff compared to the academic papers it is based on. These days I would rather spend 2 hours reading a good book or paper than 10 minutes watching an engagement-optimized edutainment video.
And for the really good stuff you have to go even more legacy – conversation with an expert. A medium older even than books. That’s where you get the stuff that hasn’t made it into papers yet, let alone the downstream half-digested edutainment stuff.