A big part of the web still (sadly) relies on flash. Be it content delivery (vimeo, youtube) or webpages. And even sadder than this its the fact that many that support html5 dont support open codecs (ie .webm, .ogg) or block content for other reasons (ie youtube).
And google doesn't push to the right direction too much.
As long as there is no major revision of the flash format is coming out (and everybody jumps on using it) I can actually live with the current flash plugin until it goes away on it's own.
Why doesn't Mozilla Firefox support PPAPI (Pepper)?
The official answer is that Mozilla devs are anti-running plugins in the browser, and would rather encourage all future work to get added into HTML5.
They're just leaving the old plugin API around for backwards compatibility and to keep from breaking the web.
Also, there's the fact that Pepper is an API designed and controlled by Google, which isn't necessarily a bad thing, but when there are currently 0 apps (now 1) that use it there isn't a whole lot of incentive to spend the thousands of man hours it would take to implement.
I stopped using Flash when I upgraded to Fedora 16 and have instead been opting for WebM and downloading some video content with KeepVid. It is the main reason I keep Firefox around, other than for having one browser without a script blocker (I primarily use Chromium, which does not support WebM).
My only real complaint is that it does still seem to be kind of demanding on the CPU when I am playing YouTube videos. For instance, I was watching a Let's Play for a while and I kept having to log in to Blackbox or LXDE to get it to play full-screen without lags. I also can not play any videos that play advertisements, but to me that is more of a feature than a fault.
That would mean we block out basically 50% (estimated, I think no one knows concrete numbers) of the web content, Flash is not only for videos, but also for applications and games.
Uh no, I haven't had Flash installed on any of the 4 comps I have for over 2 years now, I never have a problem as I don't bother with Pop-cap games. I'd say Flash is used to make 5% of the actual content and 70% of the ads. Everything else can be found elsewhere not bound up in flash if you just bother to look for it instead of following the herd, which you shouldn't be doing anyways, you run Linux like the rest of us...
The point is, obviously, to not be able to avoid ads.
If that is so, they failed horribly. If the content with advertisements was in WebM format, then I would be content with watching it, and so I would see the ads. But since it's in Flash, I can't watch it (it crashes every 5 minutes or so) - therefore I am forced to use something else, like VLC, to watch it, and guess what, it doesn't display the ads!