Well I think investing in ETH is associated with a trust into the decentralised world. Bitcoin in the end is only a currency. But Ethereum represents the ignition of a new world of possibilities. It has been the very first fully operative decentralised world. So in some way I truly believe in the long term that bitcoin will lose its attractiveness because a massive adoption is not feasible. Imagine a world where more than just a few million people try to have a transaction. The network would be totally overwhelmed.
Bitcoin is the first of its generation that used so much ink, but I think it is already obsolete due to its limited white paper. New technologies, technologies that consume less energy and offer more possibilities than only an exchange of currency as a value, will someday take the advantage over bitcoin. And with that view Ethereum is one of those possible technology that could make the expected work.
But of course those are only personal thoughts and believes, and of course I may be wrong. I just wanted to share it with you regarding the interesting post you made.