If Vitalik Buterin sold all of his Ethereums, then Ethereum price would be affected by it very seriously I think. Because I guess that he is the one who has the biggest amount of Ethereums in the world. Maybe he will continue to HODL his coins forever or sell only a small amount of it. Otherwise, I agree that the community will be angry at him and lose their belief in him.
when Vitalik Buterin sells all its Ethereum assets. I guess this could affect the crypto economy. but I don't think that will happen, crypto's popularity can be destroyed just because it's vital. surely the ethereum devs can conclude the consequences if they sell ethereum assets..
But in the first place, do you think Vitalik will resort to that path? I don't think he will intentionally ruin what he created in this community. If in case he will do that, I am certain there has valid reason. But so far, I am not seeing that happening. Because once it happens, we know eth network will disappear. Eth is pursuing towards their The Merge -
https://www.coindesk.com/tech/2021/10/13/ethereums-latest-progress-toward-proof-of-stake/, so right now, they are still actively developing this network to accommodate the need of users.