I watch a lot of twitch, probably more than I should honestly, and while the platform has problems it's really not that bad. I rarely ever have issues with 1080p streams, honestly basically never. They don't really ever buffer or stutter at all. So I don't know where that issue is coming from for you. I can watch multiple 1080p60 streams in parallel just fine. Typically watching multiple perspectives of the same game, none of them buffer.

As for the usability issues you mentioned to switch from live to vod, and back, that's kinda fair. I also don't think it's all that bad, but it is somewhat inconvenient. You don't need to type in '/videos' though as you seem to suggest, you can just click on the channel name, then the videos-tab is right there that contains all 'past broadcasts'.

What the platform does right is discoverability and user interaction. If I wanted to watch live gameplay of some game, and I went to YouTube, I wouldn't even know how to find streams of it at all. Also when following someone on twitch, I can be informed that he's going live (notification or even mail), wifi im pretty sure it's impossible on YouTube. User interaction is also just not there. I really wish other platforms were viable, cause competition eventually causes everyone to just do better, but nobody else seems to even tryn to take a share of their market...