I have wondered about this myself. BTC being the first mover allowed it to build name recognition and a critical mass of users which has driven up the price.
However, there are disadvantages to being the first mover. Sometimes the first mover ends being the first to fail. There are advantages to being second and the advantage is being able to learn from the mistakes of the first mover.
Most of the new cryptocurrencies out there address some initial weakness of BTC. Whether it be speed of the transaction, choosing proof of work vs proof of stake, or technical capabilities like smart contract integration.
Sometimes the ones that come later end up winning, Facebook was definitely not the first social network.
Myspace what? lol. You are correct.. I think there is a strong possibility that BTC could die... and BCH or even its successor could take it's place. In a technological field you must keep advancing your technology to stay ahead bitcoin has failed to do this.