Hello Trami
No, I don't think crypto will be mainstream for 2019, but for 2022 . People need time to understand how to use cryptocurrency
Why do you think so? It depends on what you consider to be a mainstream. The quantity of ICOs is growing every year. So I think that crypto can highly possible be mainstream.
But this will not be as great mainstream as some off-line ones are. Because there are still many countries where even other digital money are not used. So crypto will be too difficult for them to understand and accept.
And I see a great disadvantage of crypto mainstreaming. That's where quantity doesn't result in quality

There are still not so many teams/managers who can lead an ICO to a desired result. Many ICOs still fail nowadays.