The cost of an iPhone, or your clothes, or food, or most things you buy in your day to day life (assuming you live in a high GDP-per-capita country), is disproportionately low relative to the amount of human time taken to make that product.
That's because most labor going into mass manufacturing is of poorer people. If they were not willing to work for low wages, an iPhone would cost a ridiculous amount of money. And also most other goods. So people in more developed countries would be poorer, and the cost of goods ends up being a bit of a zero sum game: someone has to do the labor, and they need to be cheap for us to have the nice lives which we do in developed countries.
If this is true, the only way to create broadly distributed economic growth (as measured in goods and services; not cash) is to massively increase human productivity across a broad range of economically productive activities. We can't simply look at the past and try to replicate pro-growth policies which helped China or Singapore: we have to look beyond those policies. Those policies take us to a world where everything simply gets more expensive.
The biggest levers to increases in human productivity usually come from technology. So if you're a big believer in broadly distributed economic growth, I think you should be considering what kinds of science or technology careers could make a dent in global economic growth. AI is a clear example, but there are likely others.
What do you think are some good ways to make a dent in total factor productivity?
Well, capital accumulation does raise productivity, so traditional pro-growth policies are not useless. But they are not enough, as you argue.
Ultimately, we need either technologies that directly raise productivity (like atomically precise manufacturing, fusion energy or other cheap energy source) or technologies that accelerate R&D and commercial adoption. Apart from AI and increasing global population, I can think of four:
As I understand it, WIll MacAskill pointed out in Doing Good Better that people doing such low-pay work are actually utilizing a relatively great opportunity in their country and that the seemingly low-pay is actually valuable in their country.