Is the <g> element redundant in SVG?

I wonder if someone can help me. I am trying to figure out what purpose the 
<g> element serves in SVG 1.0.

I am not asking how to use it. That I understand. At least I think I do. :)

But why is the <g> element there at all? Since the <svg> element can be 
nested and implicitly groups elements nested within it what is the unique 
value that the <g> element adds?

Am I missing some obvious unique aspect of the <g> element? Or could it 
simply be deleted from SVG 1.0 with no loss and nested <svg> elements serve 
the same purpose?

Andrew Watt