I think individualism is the most convenient theory I have come across, but it is at the same time only infallible in fiction. It is straight forward and responsible. It is a very objective understanding of reality, which for me doesn't jive. It is a great tool for pointing out how dependent others are on a systems, organizations, or belonging institutions. It rarely reveals the importance of dependence or acknowledges the value in help. What it doesn't account very well for is dealing with the consequences when people aren't being "responsible" individuals. We are a species that is dependent on our senses and responding to others. We are also an impulsive group of beings. Reality is not very objective for me, and I find it impossible to see how the world can be so clear cut for others.
In society we have institutions that deal with the consequences of those who are struggling to contribute to society in healthy ways. There are governmental and private systems that serve these populations. In most cases these are passionate people who believe in helping. It is a very devalued way to earn a living. But these people organize and collectively contribute to helping those who live in the reality that life is not a simple series of objective decisions that lead to accountability and healthy outcomes. I am happy for those people who have the fortunate communities that reflect a belief that they are being successful "individuals". I am discouraged when self centeredness is called being a good individual. The line in-between is thin and how you perceive it is extremely "subjective". I don't devalue my individuality but I aspire to live interconnected.