I think user above you seem didn't know what he is saying.

Maybe he mean no officials youtube apps.
Because google become a..hole they block every thing for windows phone. Of course there is no chrome. No big deal.

1. YouTube - there are many third party apps superior than android youtube apps. I'm using tubecast pro. I think much better than my wife oppo R7s YouTubeapps.
2. Now I'm using win10 so edge is quite good for browser.
3. Why he saying no video player o don't know. I'm using vlc or moli player.
4. Lesser apps I agree but not effect my usage at all.

You can try windows 10 mobile official release.
But now I'm using Redstone build for my L830. Maybe will buy new windows phone later or next year. Not interested in L950.

If you want good experience, try L1520.
Last month using my L1520 but broken due to electric short circuit. Now using my wife 830 and feel not as smooth as 1520.
If win8.1 there is no problem. Maybe Redstone is not fully optimise yet.

There is instagram apps. INSTAGRAM (BETA).

For win10mobile. Its there.

Seem Ok but take time to load at first.