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)
Considering how much of the Internet is now backed by AWS… yeah good luck with a full, 100% boycott, unless you’re willing to install a plug-in to let you know which parts of the web are on AWS and specifically avoid them.
That being said, a 100% boycott is borderline puritanical. It’s very easy to order nothing from Amazon, and if enough of us do it will make a noticeable dent in their profits.