No one is owed anything. There is no such thing as a divine contract with the universe that says you must have or are owed a partner. TBH, I have never heard of incels before.
Relationships are very complicated to describe. I don't think every person needs or even wants a partner, let alone deserves one. I think those are the people who only want to be in a relationship for the sake of having a relationship, and that is just plain wrong. You have to love the other person for it to be a successful relationship where you are both happy. (There are also other factors, but they don't relate to this thread.) Some people know they are capable under the right circumstances, but are unable to project this kind of positivity to their present state. Instead, they lament the present status and project it to their future, thus making themselves unattractive partners, personalitywise. I guess they claim they "deserve" someone, but in reality they don't believe it and thus don't allow themselves to attract a partner.
You have to have a certain capacity of love to be able to show to the outside, to let them know subliminally that you are ready for a partner. Question is, how do you do that when you don't have anyone or anything to love? It is a massive cliché, but you should be able to love yourself. Not in the lovey-dovey, sexual, mystical or esoteric way, but you must have made peace with yourself and the way you are. Because if you hate yourself, how are you going to convince others that you are worth the effort of loving you?