Yes, Etherium is very cool and it can do a whole bunch of really cool things! But on the other hand, it can't replace Bitcoin. It's too heavy, transactions are too large, the network can't hope to handle the number transactions per minute that Bitcoin does. I think most people agree that the two systems compliment each other, they each work well in their niche, but couldn't do the others' job.
So yeah, I don't see Etherium replacing Bitcoin. Perhaps a layer-2 could, but I have yet to see any that offer the kind of tangible improvements that would really make it stand out.