Earlier quoted context omitted.
Bitcoin is never going to change from PoW... That's the point of the system, Bitcoin is unchangable, unlike Ethereum. But you are free to create your own PoS cryptocurrency. If some PoS system offers the same security features as Bitcoin, people will just switch from Bitcoin to that.
Security is not the main reason for Bitcoin's success within the cryptocurrency scene, it's that it's the first and most recognizable name. But because its creator is AWOL it's incredibly difficult to push for any fundamental change to the protocol without creating huge divisions and probably a very controversial fork (of which there already have been a few). Unless Satoshi themselves decides to make a comeback, I do…
Wrong. Bitcoin has the most security because it has network effect. Most people hop onto the most secure chain, which is Bitcoin, which increases its security. That's what network effect in this context means.