Unfortunately, like with democracy, we underestimate the power of credentialism and self-protective cults in group systems. There needs to be a randomization factor that picks people outside the democratic system to make changes or to just add new perspectives.
As for textbooks, the greatest loss to learning has been the loss of trade catalogs and the hyperglossing of trade magazines to enhance advertising over content.
In most fields before the internet, textbooks could easily have been replaced by these media. Now, there seems to be a competitive fanatical quest for new books that tell us nothing new, and a conspiracy by volume of disinformation online to keep people anxious and ignorant. It’s highly profitable, but there’s no future in it for the species.