Who won the Vietnam War? It is not at all clear that the US military could defeat a committed domestic guerrilla force. Especially if the military was split on the nature of the conflict. A bloodless political revolution is possible and there’s historical precedent for it wrt socialist movements, although expect a civil war of some kind. The fallacy that socialists just want to wage a bloody civil war in order to get free healthcare is so tired and fake and divorced from anything but liberal delusions.

Also the arms are needed to defend the political and social revolution, which will be directly attacked by armed thugs and reactionaries if it managed to gain traction toward actually upending the capitalist system. Look up The Deacons of Defense and the history of defending civil rights orgs and leaders, while kicking the Klan out of southern mainstream political life. Its not optional. However individuals armed is meaningless, there needs to be civil defense groups and left wing militias to be able to actually protect the people that need protected when they become targets of attack.