I have seen my painting skills increase over the past 5 years. That wouldn’t happen if someone else painted them.
If I paint the miniatures then I feel a connection to them. They fit MY vision, exactly as I see it, not someone else’ interpretation of my vision.
It would also feel like cheating.
BUT: My lead mountain is more of a mole-hill. I got excited and bought a load of 6mm miniatures, but now am working my way through them before ordering more. (A white lie, as I have ordered some for Christmas).