I don't trust anyone who unironically talks about "upselling" like it's a good thing.
To me, upselling is that thing where the salesperson says, "hey, have you considered buying more? No? Well you should definitely buy more." No, I don't want it. "Are you sure? I'm looking out for your best interest here! It'll be better if you buy more." They aren't. Not above theirs. And that's fair enough, but don't blow smoke up my ass about it.
There are many great reasons to buy less rather than more. None of those matter on the selling side, at least short-term. Nobody likes to be told to buy less, either. Because of that I expect sales to bias in favor of buy more even when it makes no sense for the buyer — because that frequently makes enough sense for the seller.
This seems unkind, but it is true to how I understand upselling. I wonder what salespeople think upselling means.