Both will co-exist in my opinion, so no matter what platform you invest you will still gain and book a profit as long as you investment on a solid project.
Why 2020? 2019 is still a perfect time although we are still in the bearish market, ICO will thrive as long as they are no short of investors or new blood willing to pour their hard earn money on the ecosystem.
Although there are a lot of scammy ICO in the past, investors are getting smart and will not just invest money on a poorly initiated project. Due diligence and common sense and intelligence helps a lot of investors in 2018 to stay away from scams and I'm sure they will continue to do so and invest on projects with real life usage so I wouldn't be surprised if billions of dollars will flow again this year for ICO.