A dictionary citation form is a studio take: one speaker, one tempo, no overlap. That is useful as a sketch. It is a poor model of the speech you will actually hear.
YouTube captions let you jump to the moment a word is said by a stranger who was not performing for a learner. Vowels shrink. Pitch moves. Fillers show up. Japanese です often loses its u. English schedule splits by region.
Tubonics searches the caption index first, then offers more examples from YouTube when the local corpus is thin. Slow the clip, loop the caption window, and shadow the line — the point is the messiness, not a cleaner recording of the same lemma.