He isn't even using YouTube's APIs. From the dev himself:
> I’ve said from the initial launch, Juno is built as a web-wrapper for YouTube, akin to a browser extension, and purposefully built with full respect for the YouTube website and experience, and as a result does not block ads in any capacity, nor does it introduce extra functionality like downloading videos offline that could facilitate that. Further, Juno doesn’t even use any YouTube APIs, as it has no need to: it just wraps the website, and uses CSS and JavaScript to style the website and functionality more in line with visionOS. This is in contrast to other third-party tools that for instance scrape the YouTube website for applicable video URLs and use those directly, or those that integrate ad-blocking functionality.
> I’ve said from the initial launch, Juno is built as a web-wrapper for YouTube, akin to a browser extension, and purposefully built with full respect for the YouTube website and experience, and as a result does not block ads in any capacity, nor does it introduce extra functionality like downloading videos offline that could facilitate that. Further, Juno doesn’t even use any YouTube APIs, as it has no need to: it just wraps the website, and uses CSS and JavaScript to style the website and functionality more in line with visionOS. This is in contrast to other third-party tools that for instance scrape the YouTube website for applicable video URLs and use those directly, or those that integrate ad-blocking functionality.
https://christianselig.com/2024/06/announcing-juno-2/#lastly...