I don't know about an altcoin that will overtake Bitcoin, but I know of an altcoin that will takeover other altcoins.
barr.me
Eth or XMR?
XMR most likely.
A lot of projects such as ETH and DASH only really exist because they've found a way of pumping money into supporting their existence. It's a case of life-support-machine mechanics: The heart is beating but without support it would simply die.
There's simply no substitution for a large genuine community, and that is why XMR always has the edge, as well as having the better technology anyway.
As for Bytecoin, well classic example right there: It has a high market cap, but only because it exists on HitBTC which is an exchange controlled by the BCN developers. Remove the curtain, and becomes painfully obvious that no-one actually uses Bytecoin at all. It literally has no community whatsoever.
So it's important to be wary of smoke, mirrors and hype that is derived from money pits rather than solid roots.
