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.

I'll take one pdf of this video please.

How do you power your drives on a cross country drive? How do they handle the bumps and the vibrations?

Also, it's rougly the same as why it's easier to pay for streaming services instead of downloading your media or obtaining a physical copy, and managing that.
Don't get me wrong, I don't use neither spofity, netflix, or anything like that, but downloading the media and transferring it to your mobile device is often not that easy, and always takes time, especially the first few times while you're getting used to it. And then also don't forget that a lot don't even have real computers, just a phone, and good luck to connect a hard drive to that