Actually the Tesla boycott has been quite impactful. Precisely because it was targeted at a key figure in the Trump circus. The shareholders are furious and even Musk has clearly been shaken by the impact.
Bezos is also aligning himself very closely and publicly with Trump and so is a sensible target for boycott and protest. What he has done with the Washington Post is revolting and undemocratic. He also is only so wealthy because he treats his workers so poorly.
I think a decent targeted boycott of Amazon is far better than a vague boycott of anything American