Altruism is almost always false. It's usually selfish. People do things which are, on the surface, selfless and benevolent. But they do them because it makes them feel better in some way, or to assuage guilt, due to peer pressure, or increasingly due to pathological virtue signalling.
It's not necessarily bad when someone does something "altruistic" for these reasons, but the people who are the most visible and vocal about it are the ones who are the least honest about it. They are gaining (or at least think they are gaining) the most social credit, and they expect the most reciprocation. If you do something "kind" but expect or demand recognition, you're not altruistic; you're just taking your payment in other ways.
This manifests in myriad ways we've all seen: church bake sale tyrants, celebrity cause-o-holics, corporate misdirectors, activism tourists, etc. It's only altruism if it costs you something and you gain nothing in return. Even if you quietly and anonymously help others, but in turn sleep better at night and feel beatific, you're gaining something. If you think it'll get you into heaven or some other incorporeal reward, you're being selfish.
In almost all cases, this is a good thing, but true altruism doesn't exist.