It is true that 2018 is a mainstream year, with a very long decline in bitcoin prices and but bitcoin already has a high price and I think it will increase again by the end of this year.
Yeah Making Crypo go mainstream may just be they way to keep it alive.
Well bitcoin or any other crypto currency if not mainstreamed will also be in the market with no real effect, although a black market might surface in the aftermath of getting banned from every country but I dont think its necessary for bitcoin or any other crypto currency to be centralized or mainstreamed in order to keep them alive, until and unless there are traders and investers who are earning profits from cryptos , cryptos wont die.