Hey! That's not a bad concern. I was thinking about it one day, what came to my mind was:
-We won't get salary in BTC unless it's ULTRA stable like one price f.e 1BTC=10.000$ and nothing will change it (it's impossible tho)
-Blockchain technology is NOT a new technology, it's just hot topic right now and people are able to find usage for it. I think it's a game breaker and will revolutionize few industries.
-Will blockchain end slavery? I really hope so, it has potential it depends on our will how we want to use it.
To sum up, I hope decentralized world will become a thing, although BTC is like representant but not a currency which will lead for ever (of course all of this sentences are IMO, you can disagree).
To say true I totally agree with you but only thing I can't understand here is why BTC is still leading. We have so many IT guys around the world and no one makes it better. Ethereum - does not work properly. Other ICO - 99 proc. scam not speaking about folks that say: Ohh I will change the world but give me few years I need to think on it :)