A friend asked me recently if I think that self-improvement is selfish. My short answer was that building up your character is a matter of cultivating your higher self rather than gratifying your lower self, so this activity might exist beyond the dichotomy of egoism vs. altruism.
Here’s an analogy that’s fresh in my mind because I travelled on a commercial airline flight recently: in the unlikely event of a loss of cabin pressure, oxygen masks will be released from the panel above your head and if you need to assist another passenger make sure to put on your own mask first!
You can’t truly and lastingly benefit those you care about unless you’re living well yourself: seeking wisdom, paying attention, thinking carefully, communicating clearly, listening closely, empathizing generously, avoiding anger and contempt and other negative emotions, maintaining mature coping skills, staying serene, investing in your relationships, and so on. I suppose that improving your practices in all of these areas is selfish in one sense because you’re creating a better self, but it’s also the greatest gift you can give to the people you love because you’re bringing a better self to all of your interactions.
Merely theoretical philosophers love to argue and debate about false alternatives like egoism vs. altruism, whereas practical philosophers relish jumping into the manifest complexities of actively achieving a better self and applying those better practices in the real world. The pursuit of wisdom is not a spectator sport!