That’s assuming those are the alternatives. If the alternative is instead to show you something you’ve already ordered or nothing, the odds of you ordering again if you see the thing you’ve ordered already are small, but nonzero.
In a perfect world for targeting sales, they will predict and show you exactly what it is you want to buy next. Repurchasing is just a very lazy way of predicting what you'll buy next.
(I find it super annoying, too; but that doesn't mean folks have figured out purchase reco's at scale)