There are a number of factors involved in making a 3D object look realistic (I’m assuming that’s what you’re talking about, that it doesn’t look realistic.)
Texture painting is one factor, but form and lighting each contribute about the same amount to a final product and may turn out to be even more important than texture.
I did some experiments a while back with rough hand-painted textures thinking I’d end up with a very cartoony look, but I didn’t. It was very close to realism which surprised me. So I’m thinking it may be more about lighting and form.
Can you post a render of your WIP? Perhaps that will help shed light (no pun intended) on what’s happening.
