>>182880504chan largely assimilates it's newfags, the qualities passed down from cohort to cohort are remarkably consistent for a website of that size.
I don't think the sharty will last as long because it is themed, and has each boards' post count displayed on the home page. New 'teens beeline to /soy/, engage in soyjak culture (inherently finite), and after growing bored, they leave, or perhaps lashing out at the site before leaving.
Its community is far less total.