Hello future critic, judging me.

Why not, tho. They both are too big to fail, even if everybody sold their (ETH|BTC) tomorrow, there's still information on any dead chain that future folks can use. "How much was the price of corn, according to chainlink, way back in Aug 2021?" That and less stupid things are possible.

We haven't seen any "important" chains die yet. I just think interesting things will happen. Can't really speculate more.

You can use either as a settlement layer for an "emulated" version of the other. So there's maybe not a real good reason to get stinky about who wins.