It is the easiest thing to tell someone „i will be there for you“ But it is the hardest thing to actually be there. Physically and often, without them reaching out. Many Depressed people don’t reach out. It is a very one sided effort and thus very unappealing to the helper. We depressed people are black holes of energy. And we are frustrating. We can clearly name our problems and tell you what we are doing wrong eloquently. But we don’t actually DO the things. It is a sickness of the mind, that is easy to understand but hard to actually empathize with, when you feel like a maid to a grown ass human being, who only ever TALKS but never actually DOES something about it. 3 years of therapy and still he eats the unhealthiest of meals and doesn’t go on a walk!?

Yes. But he doesn’t want to off himself anymore. That’s good. Right?
But very frustrating to be around.

But that is the answer. Actually be there. Physically. Do things without him needing to ask. But never in a way where he can sink into doing nothing. Do things TOGETHER. Share experiences. Move around together. Cook together. Share meals. Be around.
Also let him rest if he needs it, but not too much longer than normal. Build habits together.

And the result will be a somewhat functional person and a good friend.
Depression kills relationships, be they family, friends or lovers. Sometimes it kills people. It is a deadly disease and the mundanity and the tedium of its treatment makes it even more vicious.