I’ve heard that supercell is unsure what the defined purpose of the builder base is. I really like the idea of the builder base as a supplement to the main base, as it has done with OTTO hut, gem mine building, etc. I was thinking that this identity could be added onto, for example to earn training potions, books, maybe skins, etc. How this would work would have to be fleshed out of course, so it wouldn’t be one dimensional like collecting gems from the gem mine.
So the builder base would be ‘useful’ instead of just a useless village, but it would not be necessary to play the main base. This would also give the builder base a defined and distinct identity.