Can someone help me understand please?!?!?!?

So I’m genuinely not understanding why, if you take medication for anxiety and depression, why do you still suffer with anxiety and depression daily or weekly? Doesn’t that mean the medication is not doing what it’s supposed to? My husband is constantly saying he is dealing with it but also takes multiple medications for it. I try to be very understanding and supportive but I have asked him this and he says it just helps the anxiety or depression be less than what it would be, but yet he still lays in bed for hours suffering with it? It sucks because I end up doing everything for us and the kids while he feels this way and it happens frequently, and he says nothing else can be done about it. Can someone who has personal experience with anxiety and depression help me understand?