As far as the technology backing it, youtube is far superior than both of the competitors listed on here. They just need to further develop the peripherals to allow for better community growth and interaction, as well as better monetizing, like twitch does with subscribing.
Twitch does all that stuff better than youtube, but is one of the most unstable and buggiest live streaming platforms out there. The only reason Twitch is still so big is because it's been around for so long and was one of the first to jump in on the live streaming/gaming market back when it was justin.tv
If Twitch.tv came out today, as a new platform, with all the problems it experiences on a daily basis, people would laugh it down so hard and move on in a week.