The phone chooses, the television plays
Find the anime on the phone, press Watch now, pick the service for your country, and use the cast icon in that service's player: Chromecast from Android, AirPlay from an iPhone, the built-in cast on Samsung and LG. The stream goes to the television in HD with the same audio menu, and the phone stays free as the remote with My List open.
Television browsers and PCs
Android TV, Google TV and Fire TV's browser open the site directly; Watch now opens the anime in the service's TV app. On a PC, any browser opens the site and the app installs from the address bar.
A long run on a Saturday
The kids TV shows were made for a television, and a Saturday of Inazuma Eleven or Beyblade Burst on the big screen is how most people first watched them.