What Is That Misty, Glowing, Saturated Look 2000s Music and Pro Videos Have? Is it just to do with the image sensor tech of the time or is it a deliberate effect? What is it called?

A lot of music and pro videos shot during the 00s have that misty, glowing, saturated and grainless look throughout the entire videos, which you don't see any more.

Just a few prominent examples:

Usher - U Don't Have To Call - 
                
            

Professional ad for a facial workout DVD - 
                
            

Outkast - Hey Ya! - 
                
            

Pussycat Dolls - Don't Cha -
I don't know how much of this contributes to the effect, 
but it seems that they are applying a blurred copy of the footage with very low opacity.
Similar to this: http://digital-photography-school.com/4-easy-photoshop-techniques-to-make-your-pictures-pop