Originally, Mormonism was a speck on the map of religion. It didn't rate even a blip on the radar. I think even Joe Smith would be tickled yet surprised that his scam kept going after his death. He knew he had the charisma to draw people into his web of deceit but I doubt he ever thought Mormonism could rise to the heights it has nor the apparent respectability it has.
That makes the great and spacious building analogy sort of passe.
Mormonism needed an aggressive missionary program as a way to gain more dupes (not mere converts) and get rid of the husbands of the prophet’s secret brides. It succeeded because of its deviousness, helped along by Brigham Young. Mormon doctrine made the genocide go down easy, as it makes everything else you know is wrong go down easy. Jesus has a “get out of hell free” card waiting for you in the temple. Just follow orders, you’ll be fine.