The best YouTube TV app for desktops is YouTube TV.
Look up PS4 Pro Leanback UserAgent and I recommend using that with Chrome because Firefox has a little bit of bugs. If you use it as a web app it works pretty well. The one caveat is you cannot exit out of it without enabling a developer flying in Chrome, without that flag you need to use alt + f4.
You want to use a web app or kiosk mode, specifically because resolution that you get in video is determined by the window size at startup, so if you have a 4K display, it needs to be full screen at start or else you will not get 4K video. Playback, you’ll only get 1440p.
Otherwise, just full screen it, then refresh.
I personally have found that the kodi plugin is quite frankly not very good.