Socialism is unique among the other systems because it is idealistic.
In theory, the system is appealing due to its promises of equality and a social safety net. However, many socialist countries suffer from broken bureaucracies. This means that people receive poorer quality healthcare and public services due to the lack of organization. Healthcare and services are more costly in countries like the US, but they have more investment and, as a result, a more competitive market of doctors and services. Importantly, healthcare is only a single aspect of society that is stagnated by socialism.
Socialism is, in a sense, a system with the outward appeal but internal conflict. Helping each other as a community is practical when a community is small, but on a larger scale, you need more than just cooperation to succeed both nationally and internationally.