I think it is not possible for some altcoin to overcome Bitcoin. All of the altcoins are Bitcoin based. I mean, look at the exchange sites, how can you buy an altcoin? Of course through Bitcoin (and some via Ethereum). Aside from that, Bitcoin is the one who started it all. Therefore, it is the mther of all coins. And lastly, it is the only coin with unknown developers. We inly know its developer by the name of Satoshi Nakamoto.
Yes I agree it's impossible for other altcoin to overcome Bitcoin. It's like a tree, Bitcoin is the root and the altcoins are the branches. Without the root the tree will die.
It is not like that. There is no rocket science behind this fact that bitcoin is only famous just of having big profit ratios.
As now, if another coin with more profit ratio would be developed, believe me there is nothing about bitcoins would be remained on news. It is just matter of money and profits whosoever can make more that will be the king.