In terms of price, BTC isn't actually the coin with the highest of value, there's 42 coin which is expensive than BTC. But btc however is much accepted by merchants and more popular than any other coins or tokens which I don't think there is any coin popular than BTC. I have talked to some BTC investor but they didn't know Ether. A chinese in the neighborhood doesn't even have any idea what NEO is.
i think this is key; although there are faster alternatives to BTC, as well a cheaper-per-transaction offerings, BTC is the crypto that people have heard about. I think, eventually, we'll see a few mainstream cryptos, similar to how we have a few mainstream credit card companies.
Businesses will accept 3-5 crypto's, but probably not more than that. ICOs will need to find ways that people will use their coin in pretty specific industry ways (like Enjin, as an example). But ultimately, just like how your mom calls every gaming platform that will ever exist a "nintendo", some people will always ONLY associated "bitcoin" with cryptocurrencies as a whole.