What does Crypto Based their Values Upon?

And why there are so many cryptos? Other than btc what are other choices that are legit for long term? And why doge coin still held so much value eventhough it does not really have any values? So far Only bitcoin, zcash and ltc make sense to me since they all have limited cap which is not more than 1b. While xrp and others have crazy limited cap like 100b etc