I'm just calling a cat, a cat...
PlayStation Portal™ Remote Player gives you access to the games on your PS5 over your home Wi-Fi, letting you jump right into gaming without needing to play on a TV.
www.playstation.com
Also in small letters at the end of the page :
PlayStation Portal™ Remote Player can stream compatible games installed on your PS5 console. PlayStation Portal™ Remote Player requires broadband internet Wi-Fi with at least 5Mbps for use. For a better play experience, a high-speed connection of at least 15Mbps is recommended. The quality and connectivity of your play experience may vary depending on your network environment. A PS5 console and account for PlayStation Network is required. The PS5 console must be connected to a broadband internet connection, powered on fully or in Rest Mode, and it must be paired with your PlayStation Portal™ Remote Player.
So even Playstation themselves call it a Remote Player.
And well, it will be useful for people with good Internet Connection and a total waste of money for those who don't.
I understand that people would prefer a universal solution that would work 100% of the time, as a portable console or by working like the Wii U controller worked with direct connection to the console.