You pose a deep question but I am not really qualified to answer it.

There are people who because of their upbringing grow up hating themselves. This is something they were taught. Perhaps their parents were raised the same way.

Hating oneself, consciously or unconsciously, can leave a person feeling empty inside even abandoned and sometimes with a feeling of being in danger.

People raised this way often crave being with others in an extremely needy way. [I am not saying this is you. I am speaking in generalities.] Ironically for a person too needy, this can actually result in people trying to get away from them, in people shunning them.

It is almost as if they are sending a message like: "I am empty, I am worthless, I hate myself, please like me, please love me."

This kind of neediness can drive people away.

If a person loves themself, they are able to meet their needs. They seek friendship as a way of sharing the richness of their lives with others. They are generally happy, optimistic and grateful people. They can be a delight to be around and so they attract acquaintances and friends. They often make good and lasting friendships and relationships.

Sadly, people are often victims of the way they were raised as children. Some children were taught that it is good to hate oneself, that loving oneself makes one proud and that it is good to feel bad, bad to feel good. This kind of child rearing can leave a person all mixed up inside.

Such people can become perfectionists. Nothing is ever good enough for them. They strive, but the striving is joyless because it doesn't come from deep within but is simply the result of less than ideal parenting.

So, I think psychologists sometimes advice patients to work on self-love. It isn't that psychologists want people to be all alone, isolated and without friends, but they want the person to love themselves first because that is often the best road to finding meaningful relationships plus it has inestimable value for those times when one is stuck being alone, like, for example, during the pandemic or at other times.

If a person is too needy, they require another person to fill70%, 80%, 90% of their needs perhaps. This can be quite a burden on a friendship or other relationship. If a person can fill 90% of their needs on their own, they are not such a burden to others and this can actually make them attractive to others.

If we strive to be loving people, we cannot exclude ourselves. We cannot be loving people if we hate ourselves or don't love ourselves sufficiently.

Anyway . . . this is what I was taught by psychologists. Perhaps this is incorrect.

Hopefully others here with more knowledge, experience, insight and wisdom will see your post and understand it better and respond with better and more helpful words than my poor words! My English is not that great and so I have perhaps misunderstood what you were trying to say and ask. Best wishes to you in any case. Yao Wen