Great, let's all bulk buy all things we need before boycott, and then bulk restock after it. Boycotts on a population level only work when they occur naturally due to a better/cheaper alternative, what this does is only shift purchases to before/after boycott. I myself have already moved away from amazon in favor of smaller web stores, but I doubt most normal people care.
The only way I can see a "boycott" ever working is if we're talking about physical stores and people agree to literally steal, the demand gets satisfied and stores get nothing.