Google was solely responsible for YouTube's ultimate success and they deserve the credit accordingly. It was a dead company if they didn't buy it, they were rapidly bleeding to death financially and the legal picture was disastrous. It was viewed as a stupid mistake of a purchase in part because the argument was they would be a giant red ink pit forever. The sole reason YouTube survived the legal attack was due to Google's enormous resources and market position. Without that, the music cartel and Hollywood would have made sure to kill it or buy it (same difference).

The mobile picture is a lot less clear. Perhaps a dominant open source solution would have emerged. Samsung has shown itself to be mediocre at producing competitive origination platforms, so I'm highly skeptical they'd have produced the big leading platform. Apple's iOS would have never held the dominate market share, because they're universally the high profit small share player. China only came on in the last few years in terms of their ability to originate such a platform, and the rest of the planet is simply not going to adopt a Chinese platform as the 85% global market solution. The Europeans have been entirely absent post Nokia's implosion. So who else was going to fund the expensive creation of and shepherding of something like Android? Nobody. Google deserves vast credit for that accordingly as well.