I have an LG C1 OLED TV and use Apple TV device with it. Picture is great. I’ve never used any of the apps that are with the “smart” part of the TV, so can’t compare to that. I’ve always used an external device for streaming with every TV.

I used Roku devices up until about 7 years ago, and then I switched to Apple TV. The Rokus were fine at first, but I ended up having all kinds of problems with them. I don’t recall now what those problems were since it was so long ago, but I did have the Roku Ultra. I think it was the first model Roku Ultra they came out with at the time. Haven’t had any problems with Apple TV.

I’ve had Plex installed on my Apple TV for years. There’s an official Plex app in the App Store.