Improve picture quality

I just switched from AT&T TV, and I’m having a hard time getting used to the picture quality. I have 3 HDHomeRun Primes, and I’m using a 2017 Nvidia Shield as my server. I use an Apple TV 4K for the majority of my viewing with Deinterlacing mode and and video driver set to experimental, I also have have the Apple TV set to 4K SDR with Mach frame rate set to on. Is there anyway to improve the picture, or is this as good as it gets? Also, Everything is hardwired with gigabit Internet.

That's probably the best it is going to get. Is it any better in the official HDHomeRun app?

Who is your cable provider? Maybe the streams are really compressed.

Xfinity. No, it’s not any better in the official app, so I figured this was probably as good as it was going to get.