How long these altcoins you mentioned will last is another question if you are looking for its longevity, Ethereum was an instant hit when all the scam projects could use that to collect money and there was a time when Vitalik Buterin was bashing bitcoin about its high fees at one point and he was very vocal about Ethereum and now what happened, he had to swallow his words and hide  . In short as long as projects or companies are using these platforms they will have some valuation and the possibility to go down to zero are high and that is not the case with bitcoin and that is the biggest difference between bitcoin and the rest.

@OP I do accept most of the things you mentioned but i do not agree with the store-of-value part.