For sure, Vitalik being there plays an important role in the Ethereum community. But let’s assume that he decides to leave tomorrow and leave Ethereum for the rest of the team, I think that Ethereum will still be able to survive. Take for example, when Satoshi left the cryptocurrency community, a lot of people must have felt that it was over, but the community still continued and it never failed till today.
So Vitalik is going to leave as well, I believe he must have trained a lot of people who are as good as he is and they will be ready to take in case he should decide to leave. And one thing that matters the most is that community remains there, that’s what keeps it going. And in the case of Vitalik its going to be different from Satoshi, because he’s still going to be there to guide them. It’s not going to be like Satoshi that is hiding his identity.
Bitcoin survived without Satoshi because no one knew his identity. But with Ethereum, that's another story. Everyone knows who created Ethereum so his disappearance will be a huge blow to the project itself. The community could find someone else to replace Vitalik, but things won't be the same. The same way Apple lost its luster after Steve Jobs died, the same could happen with Ethereum in the future. I'd be a "miracle" if Ethereum survives without Vitalik. It will show us that the project is truly decentralized and resilient, able to stand the test of time. If ETH's fate turns out to be the same as Bitcoin's in the long run, then it could last a lifetime. For now, let's focus on making Ethereum a better cryptocurrency for all by supporting it every way. Just my thoughts