No it is not dying, but it is far from profitable. It is essential for Google to own it now so it will never stop being top dog. No other company could take some of the huge losses Youtube has over the years and the fact they've taken such huge losses is why other major companies do not try and compete.
Also the person who says Facebook is dying is crazy. These powerhouses are nothing like the historic internet failures. The companies who were big when the internet still really wasn't. Facebook, Microsoft, Google and Amazon pretty much own the internet these days and can not fail due to the fingers they have in every pie. I mean the fact that Facebook has Instagram and whatsapp just means it is a brand that could never really go under. If they start to struggle in the slightest (as they did when they first floated on market) they just use financial power and internet savvy to retake their share in the market place. They also have the fact that they are the pinnacle of the internet so people will always see their company as the dream place to work, kind of like every footballer wanting to play for Man Utd, Real Madrid etc. It is what keeps them going.
Only company I can honestly see making any kind of stir within these companies in the next ten or more years is Activision. They are making huge plays in a lot of fields and it is obvious with their purchase of MLG that they are interested in streaming. But I think their interest will always be in gaming and more than likely just streaming so I'm not too sure yet.
There is always one exception to the rule though and that is Twitter.
The infrastructure Youtube has in place is unbeatable and way too much of a risk to try and even compete. And the fact that Google pretty much own online advertisement through adsense means they could crush any competitors potential earnings with ease just makes it impossible for it to ever be truelly beaten. Maybe a site will pop up and have its moment, but that would be all.