Its fundamental reason for being has been replicated successfully by the market dominant social platform -- that is pretty killer. Snap may figure out a way to pivot to recover its shareholder value but it won't be easy nor is it obvious how they will do this.
Snap has itself to blame for using a complex UX that kept a lot of casual users out. I tried it a couple of times. Could never figure out how the damn thing worked and couldn't be bothered to try harder.
I believe this was deliberate - it was a way to keep parents out and keep it appealing to teens. It is like slang, it changes every generation so that teenagers have a private language which their parents and teachers are excluded from.
Whether it was a good idea or not, I don't know. But I believe that was their thinking at least.