It's a youth tournament that totally flies under the radar in most of the world. Let's be real here, 9 out of 10 times it's a coronation ceremony for Canadian hockey superiority in a way the World Champs aren't. Given the lack of best-on-best competition otherwise these world juniors are the only regular occasion for Canadians to pat themselves on the back about how awesome Canadian hockey is vs the rest of the world. That's why it's a big deal in Canada and covered in a significant fashion.
If the Canadian media didn't cover it, hardly anyone would outside niche hockey outlets. So TSN's coverage is basically the most professional, most in-depth you're going to find, but it's also going to be Canada-centric in an extreme degree and why wouldn't it.