Actually the question is if there will be anytime a altcoin who could be better then bitcoin? So if you look at the technically site, i would say yes they are already a lot of altcoins who are much better on the technically site. But when you look at the value and the projects himself, i think no. The core developer are very smart and before they even change something they do a lot of test before it will be updatet.
I will say yes because bitcoin has ruined many investors due to huge dip in the price and now the price is almost stuck and not increasing for several months. People are converting their money to Altcoin. The prices of Altcoin are low and an investor can hold big quantity with low investment and if the price falls more the deficits will also be low and can be recovered easily.