Seriously why does boxncase work when others don't? ELI5 the economics

okay i have an mba (don’t judge, needed something after culinary school) and i’m genuinely curious

how does boxncase make money on my $50 order when sysco claims they LOSE money on anything under $1000?

is sysco lying? is boxncase operating at a loss? someone who understands distribution economics please explain

because from my perspective: truck still drives to my restaurant. driver still paid. gas still burned. so what’s different?