Because we don't do builds for other people, we do them for ourselves.
As I stated in my earlier post, there is a limit (for me) of what I will spend on gen parts for a build. It's the whole cost/benefit ratio. I try to complete my builds for less than the going sales prices on the boards, so even though I am building for me and not to sell, if circumstances dictate that I need to, I won't get hurt too bad in the process (or at all).
Case and point, my 16014 DateJust. It is 100% genuine parts aside from the ETA 2824 (granted the hands are gen Tudor, not Rolex). Took me awhile to gather all the parts, but that build cost me less than you can see others selling for here with not much more than a gen dial and crown/tube. It gives me great pleasure to see a build that does not have the same quality parts as one of mine sell for more than I have invested.
On the other hand, I have seen people do builds with 100% gen parts and spend close to what it would cost to buy the gen. That I would never do, but to each their own. Omega Planet Ocean and modern Daytona builds can easily go down that rabbit hole. I choose not to play in that space, but respect anyone who wants to take that leap, and will applaud the quality when they show it off to us.