Your brow picture and story line is similar to my experience.
I've been plucking, threading, and waxing my brows for years, and there is now a natural, shaped arch that I don't really have to mess with anymore. I still trim the insides, but there is a noticeable area of no growth that coincides with the plucked and waxed areas (and I have fairly dense, dark hair). Of course, whenever I plucked, I made darn sure to get that follicle bulb out (like yanking weeds from a garden!), so I'm fairly certain I traumatized the follicles to impede future growth.
- Summer