For a long while, Ethereum was an uncertain project that was mainly based on Bitcoin (I'm thinking 2015-2017 here).  At this point, many years after launch, it seems Ethereum the development platform is here to stay.  I wouldn't say the platform has existential risk.  It's possible of course some of the ETH 2.0 stuff don't work out (but I think it will).  If that's the case, someone would definitely for ETH 1.0 and make it work.