

Things aren’t always that simple, if Allende was alive today he would strongly disagree. The closest example we have of a socialist government coming to and staying in power through non-revolutionary means is maybe Venezuela and that still had a militaristic component to it, Hugo Chavez had the advantage of being a former military officer and had to deal with some close call coups.

First of all the question is a bit of a strawman because socialism and collectivism are not 1 to 1 the same thing. Some level of collectivism is necessary in a socialism system but only to a certain extent, just as a sustainable capitalist system can’t be 100% individualist either . A socialist country CAN be extremely collectivist, but that just depends on the culture of the country in question. Marxism is against systematic exploitation at the industrial scale, it doesn’t say we have to be spending all our time doing nice things for our neighbors 24/7.
As for why a true individualist society would suck, it would eventually end in a huge mass of undereducated people, infrastructure decay and general neglect if we assume an opportunist doesn’t immediately take over and establish a dictatorship. Some things just aren’t going to happen without collectivist coordination.