Hmmm.. this is a hard decision because I use both to follow my favorite artists online. However, I would have to say YouTube. I feel like with YouTube, you can be more creative.
With Instagram, you are just posting a photo or a short clip. On the other hand, with YouTube, you can create creative animatics. You can publish stupidly funny meme videos. Heck, you can even make your own music there and gain a following! Check out Cavetown and Dodie Clark, they both started out on YouTube as people with dreams and yet they achieved that dream by publishing their music on YouTube.
Okay, I know I’m making YouTube sound like it’s some sort of god, which it isn’t. However, I hope you get what I mean.
Thank you