I think fruit or any plant stuff growing on trees is still mainly done by hand because you can't use a harvester. It breaks too many twigs and will cause the tree to die. If there would be havesters for this kind of job you'd probably not see the drones.

If it was super great i'm sure we'd see it more already so i'm not super convinced this is the next agricultural automation shift. Let's see how adoption is going in a couple of years. Propellers are easily broken and there are definitely angles they cannot achieve with a straight arm to get the apple.