Thinking a new social network platform is destined to fail because it's a copy of something, but without the impetus that produced the original.It's the "make something people want," but more "make something they use for X." You need the original purpose. It has to be to make something that isn't itself. Myspace was mainly novelty and music, Facebook was for status minting from ivy colleges, other ones are for an exo…
TikTok would beg to differ.
You are correct about having a base, but once you grow out of that base, you can compete as a general purpose social network (ultimately an advertising/lead channel - even if only for the market of ideas).
It's all about execution and as you said, purpose. So what's FB's purpose anymore?