Cz posts on his twitter account oftenly that " slowly but surely" I am worried about it. Guys, can you predict how slowly the adoption can be achievable? would It take within 2020 and this 2020 can be remarkable in history? \
What do you mean? Adoption across the board is already happening on a large scale.
I'd actually say that a lot of technologies are already mass adopted, like bitcoin itself, and even ETH with the advent of ICOs with the ERC20 tokens that are hosted on it. A lot of people are waiting for mass adoption to happen, but I say that we may already be speaking in retrospect.
There are certain applications of blockchain tech that may not yet be mature enough, perhaps integration in terms of the regulated financial world. But that depends a lot on the actual regulations themselves and have less to do with the fundamentals of cryptos.