Now you're moving goalposts. There's a tremendous amount of knowledge of pretty much arbitrary depth on Youtube, and most is pretty well findable using their search, and Youtube is by far not the only knowledge repository out there, and many are more or less "non-proprietary", whatever exactly you mean by that.
But Youtube in particular is a service open to everyone with the barrier of entry being access to an old-ish smartphone. In very large parts of the world, that's almost everyone by now, though not everyone will get 4k quality. I can look up how to fix my bike, how to make Austrian Backhendl from scratch, to what neutron stars are made of and how exactly the physics work, even lectures by great minds in the field, and all of this has grown pretty much organically. As someone who has had to rely on local libraries exclusively because it was the 90s and there was no internet to speak of, I think that's absolutely amazing. Wikipedia is amazing, archive.org is amazing, all the millions of niche encyclopedias are amazing, PubMed and arXiv are amazing, and Google and friends are amazing and profoundly revolutionary, even with all their problems.
But you also require this to be non-proprietary, and to run on commodity tech and even more economically sustainable than Youtube, and free of low-quality content – even books can't offer that. Printing at scale is not commodity tech at all, publishing houses are extremely proprietary in every way, gatekeep to the extreme, still publish a lot of junk, pretty much anything niche is fighting to remain afloat, cheap modern paperback paper doesn't last like vellum did, and while there are public libraries in most places, these aren't sustainable on their own, they're funded by the public.
Still, books have been central to an intellectual and cultural revolution without equal, and I wouldn't discount them just on their not-libre-enough-ness. Same goes for the present-day internet – yes, there's an awful lot of junk, dark patterns, centralization, what-have-you – but internet for the masses is merely two decades old, and most people haven't even grasped its fundamentals yet, and if you don't see past the problems, you miss the fire-and-printing-press revolutionary technology and cultural leap part, and that would be a shame.