Imagine a high-tech future utopia. Maybe like Disneys Tomorrowland or Iain M. Banks' Culture series. Think about self-driving cars, colonizing Mars, augmented reality games, or whatever your imagination can come up with.
Now think about how mankind could go from here to there.
I'm very confident you believe "more efficient/powerful computers" is part of your plan. Computers had a big impact on the world. We want more of that.
There are existential problems, which puts us all at risk. An asteroid might hit earth. A pandemic might wipe out civilisation. Those problems can be tackled with more compute power. We need more of it.
Until 2001 the chip developers could deliver increasingly faster computers. Since then, computers do not get much faster, but you get more of them in one package. Thanks to parallel computation, those packages still get increasingly faster for most stuff. Now we are about to hit the power wall and the path to more compute power is unclear.