The key is 100% boycotting all services provided by a company. Wikipedia’s list of Amazon product/services as reference (https://en.wikipedia.org/wiki/List_of_Amazon_products_and_services).
Incidentally, I know entire neighborhoods that don’t have other grocery stores besides Target/Whole Foods, not to mention that AWS is the cloud computing industry standard… As a personal example, my vet-prescribed cat foods are manufactured by Purina, a subsidary of Nestlé (needless to say, a separate but also extremely evil large corporation)
What this expression refers to is a pervasive false equivalence: the idea that anything that isn’t perfect isn’t worth bothering with, or that doing something small somehow hampers a greater task (even if when it actually contributes to that greater task). It is a statement against apathy and binary thinking.
This comes up in politics and activism all the fucking time. Like “Why should I care about car emissions when freight ships produce more emissions than all the cars in the world?” The answer is simple: because you can. Do what you can, even if it’s small. That doesn’t mean forgetting about the big polluters.
If anybody is avoiding Amazon as an alternative to those things, then I agree that they need a kick in the pants. But I doubt there’s anyone out there thinking to themselves “I don’t need to take part in the revolution because I bought my cat food at CVS instead of Amazon”.