True, if the top-level sponsorship dies off, the forum generally will as well. However, I think that’s true of all fields of human endeavor though.
Those may have died off before Facebook (2011-ish) and Instagram (2014-ish) became big things. Still, the stats here were quite dire:
I am actually sympathetic to the argument that Instagram is a pretty good fit for yo-yoing because it’s so lightweight, visual and supports short video clip upload natively, as well as pictures, of course. In my mind that’s the #1 competition as of the current date. Ask teenagers you know! 