When Ursula talks, listen:
... you can a mash lot of orcs and unicorns and intergalactic wars together without actually imagining anything. One of the troubles with our culture is we do not respect and train the imagination. It needs exercise. It needs practice. You can’t tell a story unless you’ve listened to a lot of stories and then learned how to do it.
To which I'd add: a lot of different stories. That being part of the process of respecting and training the imagination. The world won't do it for us; we have to do it for ourselves.
I've written before about this tendency to mash things together and call that creativity. On some level it is, but it's also self-limiting. It begins and ends with just recombining things, and not following the implications of that to their bitter ends and new beginnings.
Just mashing things together doesn't force you to dig deep enough, to begin with the blankest possible slate. As John Cage might have said, there is not enough of nothing in it.