False distinction: books with rules are rulesbooks.
If we discount Settings, then there were only two books beyond the acorefrom TSR for AD&D in the designated comparison period (Deities & Demigods is just as much a Setting book as Ravnica), and only produced 9 books for 1E across the entire Edition (7 if we also decide to arbitrarily designate the Survival Guides as Settings, because, well, they basically are just generic environment Settings).
But as books with rules are rulebooks, then we see 13 5E books as opposed to 7 1E books (I forgot to include the Greyhawk material and it's reissue, and fair is fair), mostly much larger books at that.
The relevant point is that 5E has a faster rate of product output than 1E at the same period, and as such is a mathematical medium between a slower release schedule such as 1E, and a rapid release schedule as with 3E/4E.