In my humble opinion and experience, the easiest fruit that I’ve grown and proagated has been the Everbearing Black Mulberry.
It is extremely easy to make a clone of this variety and it is super tasty. It is also high in antioxidants.
Did I mention it’s free? Just have enough space to grow it! Ok not entirely free, but really close to it. I paid $30 for a tree a couple years ago, and have successfully made about 30 clones from it (I have about 20 at my house planted in the ground). So really each one is about a dollar. No, of course there is the cost of labor, but when you’re doing something you love, the last thing you think about is the cost of labor.