There is one problem with Ethereum. It's horribly complicated.
Does anyone know how they really work inside? Basically no article says how it functions, only what it does. You would need to go deep into whitepapers.

With Bitcoin, there is completely different story. Here is blockchain, this is how block looks like, hash goes here, mining means that... etc. Everything can be described in one YouTube video.

In my opinion this is why Ethereum will never replace Bitcoin. Too much error-prone. Developers will rather stick to something they understand better.