You wrong about that, eth will take the lead in 1 to 3 years, i do not think is time for that yet, but it will be a time where eth will be top cause is a much more complete digitalcoin than anything in the market right now.
ETH can't even handle cryptokitties. I also used to think that it was going to surpass bitcoin's market cap but right now I am not sure anymore. I think its an overpriced coin and something better (Cardano?) can replace it at anytime. ETH devs don't even comment on the upcoming PoS fork. You know why? They are afraid. ETH owes most of its popularity to GPU miners. When ETH loses its most hardcore shills (which are GPU miners btw) it'll lose its popularity lightning fast.
On the other hand Bitcoin has Lightning Network which is going to pump bitcoin even further this year or the next. When a fool proof app comes out, it will be glourious. (0 fee, 0 second payments)
While Peter Thiel is going long on bitcoin, I think it is stupid to say that it will lose its popularity.
http://bitcoinist.com/peter-thiel-long-bitcoin-neutral-everything-else/
If you have any faith in bitcoin, it makes absolutely no sense to think ETH isn't part of the package. If you are willing to compare ETH to Cardano, feel free to compare BTC to pretty much any coin that has no function. The comparisons don't work that way. The crypto sphere needs both coins to continue to grow, and they will in time.