Why don't video sites just use the video element?

Most browsers nowadays support it, and I think the browser still probably works better at buffering and stuff than a flash player does. So why go all gimmicky with javascript and flash and whatever else rather than just displaying the videos in a traditional HTML format?

Oh sure, some old browsers won't be able to use it. But guess what? Most people still using them likely won't be allowed to view videos due to being at work or something. Or won't have an up to date flash player either. Or perhaps javascript disabled/blocked.

Anyone else agree?

 

Probably in order to provide ads and one unified 'player' (otherwise it may vary between browsers)...