The problem is, most consumption is not actually flexible - it's semi-fixed cost (i.e. shelter, food, transportation). And those don't vary enough for asset acc

The problem is, most consumption is not actually flexible - it's semi-fixed cost (i.e. shelter, food, transportation). And those don't vary enough for asset accumulation to be possible at the lower end (especially when you include externality cost from things like eating cheap food). The difference between earning $100K and $500K for most developers, for example, is [most] of that extra income going into investment assets; that's because the first $100K covers most of the fixed costs, and short of luxury purchases, there's not much more you need day-to-day. The gap between earning $30K a year and $100K a year is way bigger in terms of QOL than between $100K a year and $1M a year. (I'm in between both worlds in a way since I have friends making < 30K a year and > 200K a year and I have two careers, one high income and one relatively low income and have thought about the issues quite a bit)