But BTC has indeed that 100+ advantage over anything because of being the first one and the most popular and already established.
Which is Bitcoin: BTC w/SegWit fork, the 2MB hardfork of BTC+SegWit coming, Bitcoin Cash fork, Satoshis protocol original Bitcoin?
Seems Bitcoin became an altcoin.
It's not immediately clear.
One take regards the ETH/ETC debacle. Let's forget for the moment that ETC itself is a hard fork of the original Ethereum protocol. Versus ETH, it is the original protocol. So what makes ETH the real Ethereum? Is it support from the vast majority of developers (comparable to Core)? Is it majority hashpower (I hope not)? Is it majority economic activity? Is it some composite of these things?
These aren't easy questions to answer...