Replace Apple TV

I mostly watch YouTube

Actually, the streaming devices such as AppleTV, Roku, Fire, etc. all have an absolutely crappy youtube app.  The resolution is always poor and audio quality is massively compressed.  The superior device to stream Youtube videos into a DAC is always going to be a full blown web browser from a computer (either Apple or PC based).  You should connect the computer directly to the DAC or the reclocker (bypass any AppleTV / Roku / Fire streamer for this).

If you are willing to consider a PC desktop with Windows and an AMD processor, you can look at the JCAT USB card or even a Pink Faun if you want to do S/PDIF directly.

Now if you were just playing music files or streaming from Quboz or something, I'm sure there are many players out there which are better than a desktop/laptop computer.

If I get a dedicated player, with no need for AirPlay, how do I watch the video?

You can’t. Dedicated players do not have video output.  Fuzztone did not read your requirement for watching Youtube videos.

If you read my post above, the Youtube app for streaming devices such as AppleTV is very poor quality.  Video is almost always low resolution and audio is always compressed.  You will ALWAYS get better audio from youtube on a computer web browser.

But if you want to youtube with AppleTV, go for it.

I guess it comes down to convenience vs sound quality.