Google is expanding YouTube TV to be compatible with Firefox, as seen by YourTechExplained, marking the first browser that works with Google's non-Chrome streaming service (which you also remember is owned by Google).
The additional support of Firefox comes from a silently updated support page that signals the change, although unfortunately it only seems that Firefox is getting the update from Google for now. There is no news that Safari, Edge or other browsers get the blessing of Google to work with YouTube. TV at this time.
YouTube TV costs $ 40 per month (after a recent price increase), and also has apps for iOS, Android, Apple TV and Roku, as well as Chrome and Firefox in browsers.