I suppose that a clear sign of the success of web-based mail is the fact that
I've got to run a Google search to find out what we call its predecessor (can
it be called its opposite?). Maybe we used to call it "standard",
or "regular" email. Calling it a hard-drive based email client
is more than a bit clunky, but at least it gets the point across.
But if, long ago, web-based email was considered a not-fully-legitimate little brother to that other sort of mail, I wouldn't be surprised if, other than in the enterprise, web-based mail has totally eclipsed its big brother. There must be statistics on this, but I'm not about to start looking for them, and frankly, those statistics may be paradoxically inaccurate, considering the fact that numerous studies suggest that young people apparently don't use email at all, preferring instant messaging instead. If that's the case, we might find heavier usage of hard-drive based clients not due to a preference toward them, but because email in general may be in decline. And I suppose that instant messaging should by definition be considered cloud-based, though its use also suggests a disregard for permanence, which in turn suggests that future generations aren't going to turn to the cloud, or anywhere else, for storage.