"I can't speak for anybody else...but this is why I don't offer the service: Replacement Screen - 180$. Granted I could get it cheaper wholesale but that's a lot of money just for the screen and we haven't even talked about shipping costs, inventory, warranty, labor, profits...
It's hard enough to get people to spend 100-150$ to fix an iPhone, there's not much appetite to spend 200$ + to fix a $269 watch."
"Parts are not cheap due to limited supply, and thus demand. With parts and labor this expensive, most people would just spend a couple dollars more to get Apple official repair, which guarantees parts quality and all functions repaired.