It’s simple, optus consider Apple TV as a mobile device therefore hi end streaming isn’t dedicated to that device, they want you to buy their devices to get the best stream from, not others.
They also have no idea as my username suggests.
Change your settings to 1080p 50hz not 60hz and turn off match frame rate off if you have a Sony or Phillips TV or high end as they generally adjust themselves so no need.
while you may still get judder as apple tv resampeling isnt great d still streaming at 25fps you’ll at least have a much crisper picture.
Also make sure your audio settings match your output, it all helps believe me.
I don't think it's accurate to say that Optus consider the Apple TV to be a mobile device and thus don't offer high end streaming. The EPL on demand streaming on Apple TV is bang on, no issues, it's the live feed that struggles with 25fps.
As for wanting us to buy their device, I agreed with this when EPL was only available on Optus Fetch boxes, but now that all Fetch boxes can get it, including retail boxes, that reason seems kinda irrelevant now.
I think it's more likely (as AdamTreff suggested) that Optus cannot handle hosting increased bitrate streams for live streams across multiple platforms.
Having said that, since I switched to Fetch, it hasn't missed a beat. Perfect feed, picture quality and frame rates. Optus Sport somehow has gotten worse on my Apple TV & Xbox One X. It sux to have to buy a Fetch box to watch EPL, but Optus do have the soccer rights for another 4 years so, it's a necessary evil.