Bitcoin is simple, and that's what people like. People want to store value, move value back and forth, and if possible, at low cost. Altcoins have been offering all sorts of gimmick features throughout the years, but 95% of the people aren't interested in using these features at all, which once again points out that it there is no such a thing as Bitcoin being outdated.
Another aspect I see people complain about, is that Bitcoin's transaction fees are so expensive while altcoin fees are so insanely low. Roger Ver did that too, and he even made fun of Bitcoin various times in his streams as well. People should understand that the only reason altcoins are able to offer cheap transaction fees is because barely anyone is using their networks. High fees = high demand for block space. Low fees, or even no fees = low to no demand for block space (ie, coin is practically redundant). While I don't like altcoins, I do like their presence and the global interest in them. It's impossible to point out exactly, but the altcoin market makes sure a very large number of Bitcoins are taken out of direct circulation, and that makes sure there will only be more coin scarcity in the coming years. In other words, booming altcoin market is great for Bitcoin as well.
While I agree with the OP when he says bitcoin will not be outdated by another currency, I don't agree with his analogy. It has more to do with what the user I'm quoting referred to, bitcoin is simple and that's what makes it more attractive. Also the fact that it is more established as THE original crypto, it gives value to newcomers I guess.