If you're not happy/content alone, you won't be happy/content with others - what's your opinion?

This is a popular reddit heuristic. One I'm not sure I see offline (definitely I've rarely heard people offline agree, and have heard them disagree. And I'm talking people who work in psychology). For one, I'm aware people have different values - in other words, different things bring them satisfaction. Redditor values seem to lean towards asocial ones. But also the upvote system leads to a lot of repetition of views (someone reads it's popular on one thread, figures it therefore must be true, so says it elsewhere and then starts to think it's actually their opinion they agreed with based on independent thought. Similar to now the news has the power to manipulate public opinion by saying "everyone thinks \[whatever\]". I'm also aware reddit is very American, where individualism is preached heavily (Westerners and Japanese for example literally perceive marine images differently - American minds on average focus on the main fish, Japanese minds notice the background around the fish more). It also seems weird because humans are social animals. So if alone means isolated, that contradicts human nature. Even more so the more extroverted someone is. "Loneliness" can exist with or without isolation. For cases where it's without isolation, it seems to be "not being seen" or "not being mentally or emotionally connected with" is the issue. These both seem to be human needs, considering how universal they are. So then I question how content anyone will be alone. I'd also wonder, more grimly, what would happen to the happiness levels of people with family, close friends or close partners if they lost all of these by means other than death. Would their happiness level be the same as it is, after the initial period of grief? There's also the economic and logistical benefits of connections. These aren't intrinsic to the relationship, but more a by-product of society, but are part of current reality​. Like, having a family is economically less important for survival in the UK than in some Asian or African country with zero welfare state (but I don't think the welfare state successfully replaces the economic benefits of personal relationships, including logistics).