I work in the packaging industry, and they have literally every size box, in any quantity, on demand. That being said, our clients purchase everything. We don’t have much say in what vendors they choose.
Fun fact: I throw away (recycle) 2-5 full size Uline catalogs a day, even though it says on every packing slip CUSTOMER REQUESTS NO CATALOGS.
Jokes on you, I voted weeks ago. Even tricked a few people to join me.