YouTubeTV streaming issues on older Sony XBR-65X930D TV

Been doing some digging around but not finding an answer. I have an older Sony TV XBR-65X930D. It is capable of 4K. We have 100 mb cable service. The Sony runs Android TV, not Google TV. I understand that Google TV is a better app. I have an older Yamaha AVR, RX-V867. I have had problems for a while with streaming Netflix, YouTubeTV, and YouTube and trying to get to the core of the problem. When I run these on my desktop PC, everything is snappy and quick. On the TV, it's a lot different. With YouTube, when I start watching videos, they will often be noticeably pixelated when first beginning. If I rewind 20 seconds or so, it will clear up after several seconds and then run ok. Netflix is just slow overall, but the picture quality is fine once it does start streaming. YouTubeTV is slow. I am normally watching from my library. When I start a saved program (usually sports related), the audio and video will be jerky, then the video will freeze for ten seconds while the audio continues just fine, and then the video will start and all will be ok until I skip through commercials, then it will do it again after I try to resume after skipping. If I try to use multi-view, it's just so stuttering, it's unwatchable. The same if I try 4K, which I am not doing currently. I think the cheapest resolution is to use something else besides the smart tv app for streaming and just use the TV as a "dumb TV". We have an Xbox One S, which I understand will run YouTubeTV, but I'm concerned about how easy the interface will be compared to our TV app, maybe it doesn't provide 4K? I'm not sure on that point. What other inexpensive options are out there? We have a Sony Blu-Ray player, but I don't think it will run apps. Thanks for slogging through the long read.

TLDR: What devices are available that will run streaming apps at 4K to a Sony TV?