YouTube Re-encodes the video and compresses it heavily thats why it looks bad, Try 1600x900 it's barely perceptible to the eye and will artifact much less. Also I haven't used restream but it could be the case the it is re-encoding as well. BTW if you're affiliated on Twitch restream is against your contract TOS just a heads up.
No I'm not affiliated on Twitch. Thanks for the response. I change a settings and it doesn't blur as bad now