I patently disagree!
I do not judge people solely based on the quantity or longevity of their friendships. The length of a relationship does not inform us about the nature or quality of interactions, or whether they have depth, mutual satisfaction or flourishing. Someone may remain in your life more out of habit, obligation, or convenience, rather than truly wanting to be there.
There is a difference between someone harmless with a stronger preference for solitude (asocial) and an antisocial person who is harmful and intentionally aggressive, or covertly or overtly hostile. Sometimes, toxic people are nested in strong friendship networks with multiple veils of social protection. There can also be an entourage of flying monkeys that can enable maladaptive behaviour among their inner circles. Communal narcissists may be well-liked with many friends, present themselves as exemplary citizens, and engage in performative generosity and emotional deception (masking their true intentions). Conversely, people with few to no close friends can still be worthwhile human beings with a variety of interests and a rich inner world. These individuals can be offbeat, profound, and offer refreshing insights.
Additionally, friendship formation is influenced by situational, contextual, cultural and structural forces that are often beyond an individual's control. There is a concept in sociology known as homophily, which refers to the tendency of people to prefer those with shared characteristics over those with dissimilar ones. There are barriers imposed by the challenges people face if they are highly mobile (having moved often) and never establish firm roots. Or due to language barriers (limiting them to co-nationals out of necessity). As well as the level of acculturation within a nation. Individuals who are neurodiverse may struggle to forge friendships owing to the lack of consistency and contradictions among neurotypical people. Some establish firm divides based on class, while others do so based on religion. In comparison, others discriminate based on sect or interpretation within the same faith. Some are quite insular and conscious of factors such as neighbourhood, education level, race, generation, ethnicity, or appearance.
That said, friendships are more exclusionary than they are inclusionary, partly based on time, physical, and energy limitations. They are also gated because long-established friendship circles are based on the degree of fit (conformity) and are structured around a hierarchy of closeness, typically determined by the duration of the friendship. Outsiders are often kept out and viewed with suspicion, even if their intentions are well-meaning. If they allow someone new into their circle, others may perceive a threat or worry about being cycled out. They refer to this as the politics of friendship.
Friendship networks often shrink after marriage in favour of kin, though they may expand again after divorce or the death of a spouse. Friendships also require the luxury of leisure time, which is not available to those who are unemployed or overworked, juggling multiple jobs. The pandemic and political divisions further reshaped relationships, with many choosing to distance themselves from those with opposing views. As tolerance for disharmony has decreased, more people now prefer solitude or decide to end unfulfilling friendships altogether. Friendships are always up for renegotiation, especially when effort is uneven.
What matters is authenticity, reciprocity, and freedom from deleterious harm.