Stream quality sucks when playing games that have pixelated graphics.

Hello, my name is Fernando, an independent consultant. Hope you are doing great. I will be more than happy to help you with your query today.

For broadcast you can increase the quality up to 1080p for your audience, unfortunately on console it is not possible directly.

You can increase the resolution through this procedureress the Xbox  button to open the dashboard.
Select Profile & System > Settings > General > TV & Video Options.
Under Video, select the appropriate screen resolution for your TV or monitor.

Sincerely, Fernando

This is a hardware limitation. There are algorithmns that try to guess what you're going to do, and they sometimes fail.

You can adjust the stream quality in settings>Preferences>Capture and Share

It's a game with giant pixels and you are concerned about graphics quality?

Changes from the earlier years of gaming were easy to see because everything was so pixelated. Everything looked like Minecraft. The pixels are so small now we can't even see them anymore. The quality from the 360 to the One isn't going to really stand
out very much and I don't really think the playability is going to be that much better because of it. Steam is having a very good sale right now and I bought Half Life 2 and it looks fine to me, lol. (because I'm too busy trying to survive to take the time
to notice the graphics quality) I like quality graphics as much as anyone but the changes from here on will only be subtle as long as the graphics remain on a flat screen.

Also Rocket League which is a game I play a ton it is Series S|X enhanced and on quality mode on Series S it looks like trash. I don't mind graphics hence why I bought the series s but God jaggies everywhere and looks pixelated.