Arena is a terrible way to "demo" bots and not accurate at all. What you do in arena is show your e-peen and, possibly, potential.
Uploading videos to youtube isn't any hard, all it requires is one extra step, which honestly it's better than using Twitch, as Twitch can easily make you lag in game if your connection isn't good enough to have enough bandwidth left for the game to use at all times (games doesn't need much, but games won't reserve bandwidth unless you use 2 rigs, meaning that you need several times of what the game needs to ensure you never lag).
There's streaming in youtube too btw, which automatically uploads to your account.
