> Since he’s the one buying he doesn’t need to deliver anything

This only works (in my mental model), when you produce the product you're selling in-house – like a digital product. But lots of "reselling" type businesses try to use this scheme as well. Like a restaurant might ring up more meals than they served, or less to not pay taxes. But, is this not easily spotted when the food import(?) cost doesn't match the revenue?

Maybe I just answered my own question, if the business is able to cook the books both ways, but it would also limit how much they're able to launder. Or is the import/export balance rarely/never checked?