Bitcoin is the first coin in cryptocurrency. It has created trust from investors through the price increases. I don't believe any coin can replace Bitcoin.
Electroneum is not comparable to bitcoin, bitcoin is the best amongts all cryptocurrency. I dont think electroneum will be a having a huge price in the future. Bitcoin is gaining popularity ever since and until today.
I think electroneum can't surpass bitcoin, even this altcoin is successful in the market. However this electroneum have good profile to all people so there's a possibility that in the future they have earn a lot of investors. Moreover in terms of popularity I still believe to bitcoin because due to high numbers of supporters of this coin management were continue developed this coin to attracted more investors and clients.