I think that's less a question of having ways to tell good stories and more one of a creative space being exhausted. There's a desire in a long-running series to keep raising the stakes as the series progresses, but doing so reaches a point where there's nowhere left to raise the stakes. I think that's been a bit of the problem with Doctor Who in the last few years. As they've kept raising the stakes (right up to the existence of the universe), there's nowhere left to go.