Because Grayjay allows users to follow others across multiple platforms such as Rumble, Odyssey and Twitch. So if they get banned off YouTube, they will still be able to access content on other platforms.
And with Grayjay, you can download these videos and access them without needing to connect to the internet which is required for YouTube Premium despite the content being downloaded on the YouTube app.
I'm not quite following what is your confusion when he outlined the problem Grayjay is trying to solve.
YouTube legal wants Futo to release apis and user data to them as they believe Grayjay is violating their terms.
Grayjay doesn't store user data nor is it using their APIs so the terms don't apply
Futo will not be removing Grayjay and won't be complying with a request that cannot be fulfilled.
Other details:
YouTube Premium's download feature still requires an Internet connection to access content downloaded.
Louis makes the point of being tired of paying for products and services that end up giving you less and less, which is part of the reason why Grayjay was created
Content creators shouldn't fear of being banned by an temperamental AI that could cripple their livelihood without an explanation which Grayjay attempts to solve as viewers can still access their content on Rumble, Twitch and other platforms if they get banned on Youtube.
Good on Louis for sticking to his guns.