I am not here to put my opinion on the subject of YouTube magic being good or bad (though I am going to have to discuss this). I am here to say this - There is nothing as cut and dry as your statement above would have people believe.
Have a look at your statement from last week in another thread -
https://www.theory11.com/forums/threads/lost-with-the-bottom-deal.39703/page-2#post-478520. There, you state "Ive watched some poor youtube tutorials on the subject" when referring to the bottom deal. I don't know the numbers here, but from a quick look MOST of what I see on YouTube is comprised of these poor videos. Lots of people who have little or no experience trying to act like authority figures on magic that they don't fully understand. This helps magic? On the contrary, this creates lots of non-magicians who know magic secrets, and lots of magicians who don't know how to do magic well. Neither of those things is good for magic in any way.
On the flip side, as you say,
This could be seen as a positive thing, forcing existing magicians to grow and adapt.
Two different sides to this. Saying "Magic gets better because of youtube. Period." is not true by any stretch. As always, the truth is somewhere in the middle of the two competing arguments.
If someone who does know and understand magic well enough to be teaching it can figure out how to use YouTube to teach only magicians and possibly people interested in starting magic, then YouTube could be a powerful force for benefitting magic without the major downsides. This is a lot of the reason that people release tricks through stores like theory11 in the first place - to share magic in a location where there is a barrier to entry. Of course money is also a factor, but responsible magicians understand the responsibilities they have to protect and safeguard magic secrets.
// L