Yes. If I saw data showing that 20% of youtube users didn't see the red bar, for example, I would agree with your point. But I have 1) my own experience showing otherwise (not worth that much) and 2) the logical argument that youtube probably did some usability tests with good results before releasing this. These 2 points are not a definitive argument, but they're enough for me to be skeptical of your critique.

> The progress bar within does work, because the user enters the address right there and at the moment where he presses enter,

But this is not the case when a user clicks a link at the bottom of the page, and a new page starts loading.