more gain = more dynamics or less?

I have read some in depth threads on gain and loading of sut and preamps, and I grasp parts but certainly not the whole. And I gather for every ten people who think they understand it, only a couple actually do... as evidenced when one of you heavy hitters weighs in and blows up all the misconceptions!
So without going into all the details, is it possible to generalize whether more phono gain creates more dynamic headroom, less dynamic headroom, or the same dynamic headroom? Designers seem to seek the minimum amount of gain necessary in the phono chain... but I am not sure if this is only to minimize noise? Or does it have other benefits?
Thanks.