I think it's a great idea, if to make steemit known, on all the platforms that you can.
The times I make a publication I also do it on twitter, until now no one has approached me on that platform asking something. but when I teach at the university I think I reach many more people. and always from a class where an average of 25 students attend each semester in a single section there are 2 or 3 who are interested.
Of course 2 or three is nothing compared to the scope of the on your YouTube channel