Is there any concern with PoS technology phasing out PoW? How do we know Bitcoin will be the coin to prevail? I don’t mean to fear monger, I’m very bullish on the concept, but I want to fully understand this market.

It seems to me part of Bitcoins’ hype is simply because it was the first crypto currency people saw with potential. Now that there is so much attention to the sector, what’s preventing people developing new coins with better technology that will surpass Bitcoin in relevancy? For example, Proof of Stake seems to be much more efficient than Proof of Work, but as far as I can tell that is a fundamental part of Bitcoin that cannot be changed? And I imagine there are other components that are similar?

In my head, I’m kind of making comparisons wondering if Bitcoin will be to crypto like how MySpace was to the social media world, or how Skype was to the world of virtual meetings. Is that a valid concern? If not, what makes people so confident in BTC?