If ETH reached 1k, I'd pretty much lose faith in all cryptocurrencies' ability to innovate without everyone giving up on an entire currency every couple of years.

Immutability is a great characteristic but if ETH gets that far it'll show that decentralised innovation like Bitcoin promotes is not good enough to stay dominant.

ETH 1k and Bitcoin 4k would have ETH at a higher market cap than Bitcoin (not that market cap matters, but it's the only measure I can think of).