There is a good argument to be made that increasing the GDP is a moral imperative [0]. I know it's increasingly trendy to think all of capitalism is evil and we should tear the whole global economic system down (and to tweet about it from your iPhone while sitting in your air conditioned home, eating your meal delivered by Doordash). As much as it is true that inequality is higher than it should be, and there are lots of things in the world that should be improved, it's also true that for the vast majority of people in the US and around the world, their living conditions today are much better than they would have been at any other time in history. Which is the simple result of compounding economic growth.
Talking about "changing the world" by building an app sounds a bit quaint and too self-serious these days, but I really don't think it's true that the average person working in tech contributes nothing positive to society.
[0] https://www.mercatus.org/bridge/essays/economic-growth-moral...