I hate those client apps that just open youtube on your browser.
So, windows will never have an official youtube app? We will be stuck with youtube clients?
Let me give you a link to MyTube Beta
It's still in Beta but it is to me and many other the best YouTube client. It's very smooth and very easy to navigate. It is also Built for Windows 10
https://www.microsoft.com/en-us/store/p/mytube-beta/9wzdncrdt29j
^ The feature isn't enabled yet since it is in Beta, for the moment you'll have to use another app for downloads.
But in terms of browsing and navigation, I don't think there's one that's better than MyTube Beta