[HDThoreaun]

If the pie is ten times as large, a slice that is half the relative size is still five times larger.

[uuvs8]

Indeed. But the feeling of well-being is not absolute, but relative to you socio-economic context. The average American is manitudes better off now than 200 years ago, in absolute terms. But are they just as many magnitudes more happy? No. Depending on study, happiness is significantly less.

It's not at all clear that maximizing absolute quality of life is the best ultimate goal.

[sidlls]

The relative sizes of the pie slices matter for things other than immediate material comfort/gain; for example, political power.

[SketchySeaBeast]

That's the optimistic way to look at it, sure. No reason to think the slice can't shrink faster than the pie will grow.