It doesn't say "require". Possibly they are selecting the same information over and over again, instead of passing it along the different functions, because it is fast enough.
(And just to be clear, for my use cases, I have been very happy with SQLite's performance.)
(If you’re thinking, “no dummy, just use caching” then I regret to inform you that cache invalidation and eviction without an info architecture are as hard if not harder. And caching bugs make you look like a clown in front of your bosses. Because the whack-a-mole process never looks professional)