A single person, stripped of any collective context (family, village, religion, ethnicity) in which people support one another and consider one another members of a group with duties to that group, is much weaker than one who exists within those frameworks and has sacrificed some degree of individual autonomy to do so. Of course society is reducible to the individual, but individuals derive a huge amount of advantage and benefit from various collective associations and actions. Choosing to 'go it alone' without engaging in any sort of collective action doesn't make you stronger, it makes you profoundly weaker. People can certainly choose to do so, but the idea that this isn't a sacrifice is nonsense. The more collective support and obligations you strip away, the weaker you become. Someone who pursued the extreme form of this in the middle ages (hermits) never took it as a sign of strength - it was always seen as a sacrifice.