No chance for ethereum to devalue to the zero. Protocol has become a very popular protocol and this time bunch of people owned ethereum as their investment. The potential to go down will always there but not for going to the zero value. This is not possible to happen.
Thinking about something that has become a part of people's life in the crypto to be devalued to the zero is pretty naive. People already considered ethereum as an investment.
So many address that was holding ethereum.
Yes, too many projects were at stake and part of ETH ecosystem. They of course will never let their main network go bankrupt or come to zero. Like shareholders offer to buy more stakes to keep the company going. Or investors want to buy ETH at the dip when it was cheap enough for them.