It did evolve, and yes, Google constantly experiments with/ tweaks it, as a matter of fact. I never claimed that sudden radical changes are a good idea - they are very risky, at the very least. And generate dissatisfaction even when done right.

> The rest have pretty categorically disimproved with each iteration. I doubt many would disagree here.

What? That's crazy. Both gmail and google maps have radically improved over their original versions. You're of course free to disagree, since these sorts of things are subjective; but I'm confident that you won't find a majority of users to share that opinion.