What is "real value?" So much of Bitcoin's value is tied to speculation about future usage. It would be silly to say today's price is based on current network value. The same applies to altcoins.

Just because Bitcoin is the best cryptocurrency doesn't mean it's the only valuable one. Bitcoin can't and won't integrate most features (including private/confidential transactions) for political reasons. It will never use alternative consensus or scaling mechanisms (like proof-of-___ or sharding). I think it's naive to assume that no use cases or superior technological approaches will ever emerge from altcoins.