If that is the case as you said ETH should have taken over now.
but the fact is btc is still strong in the lead, we will never know the extent of development that will occur in altcoins, but still the one who will be at the top is btc.
Though the Altcoins movements has been seen in the cryptocurrency world but that can't be said that, they will definitely out turn bitcoin from it lead. Even when there are good and promising altcoins projects, there is still none of these altcoins project that will measure up with Bitcoin. Bitcoin is the lead and nothing for now can defeat it from dorminance currently. Ethereum is good among the Altcoins but can't be compared Bitcoin.