The first mover advantage is really not the strongest part of BTC, it is the fact that its base function is store of value. Bitcoin created this feature in an unique way and no alt will ever be able to copy this.

BTC will be able to do smart contracts later on, but ETH will never be a proper store of value (rollback was a joke, decentralization demolished). I believe a platform needs store of value as base function to be finally most efficient, because then the miners are already paid, so 2nd layers can be used for (as good as) free.

In my opinion ETH can move faster because it is more centralized and not build up from the fundament (store of value), but in the long run BTC will deliver all the features better, cheaper, faster and more secure. I am not worried that ETH will take over BTC in market cap, because they use another mining algorithm and will even move to PoS (what is unproven and causes in theory more centralization).

Bcash was dangerous, because if they get more valuable they will also become more secure. For ETH this doesn't matter. Good luck overtaking BTC in market cap, it doesn't mean anything for BTC, their super exiting roadmap will just continue!