I think they're rolling this out to a small select of channels as this layout is only present on my second channel and not my main. Probably for experimenting.
My only problem is that comments are so high up now, bringing spoilers to the video. Issue from mobile now on desktop.
every time i open a yt video without having logged in im like "oh yeah how weird the ui is gonna be this time"
i swear, there are some cursed ones and this is definitely one of them