2nd amendment is a last-resort safety measure against tyranny, we should keep it while mitigating side effects, like making sure that people who buy them are sane, trained, and do not resell it outside of legal channels.
Do we need such a ridiculous safety measure? What is a chance that US can end up as a dictatorship Chinese style? Many democracies in history ended or had dictatorship periods – Romans, Germans …
Having such a safety measure is even stabilizing in normal conditions, as the country can be more tolerant towards differing opinions knowing that dictatorship is not likely.