Do you think learning on youtube and other similar sites will become more prevalent in the years to come?

As this is answer requires a personal opinion, this answer will be just that so keep that in mind. I believe that the YouTube tutorials and the ones on other sites will probably see the increase in use but that they will not be the main mode of learning as the guidance of teacher who can actually monitor your progress and help you personally will always lead better results than just watching videos.

Yes, it will become more prevalent.
The memory of tv ratings which is based on a limited sample of viewers will become comically archaic.It will be a real-time for those who will be making videos because they will have time to determine who have watched their videos and what thought they had of it.