I'd be curious what, if any, role the increasingly obviously hollow promise of progress may have.
In absolute terms residents of low-income countries are usually more fucked than those of high income ones; but in terms of trajectory they often have a somewhat rosier picture: if GDP per capita is really low you don't really have an option but to be really poor, there's just not enough productivity to support being otherwise; but there's a fairly straightforward alignment of incentives: unless there's a local supply of mineral wealth to skim, even the local elites generally want everyone to be more prosperous because there's just not that much money to be gouged out of subsistence mud farmers; and there are a variety of plausible avenues toward greater productivity in the form of people looking for new manufacturing areas and the like.
Similar things hold for various quality-of-life stuff. Low income countries tend to see a lot of morbidity and mortality from lack of relatively cheap and simple medical interventions; but have a corresponding selection of relatively cheap and simple improvements that will improve population welfare if realized.
Wealthy countries are, obviously, absolutely wealthier; but are often harder to write an optimistic trajectory for: if most of the obvious productivity improvements have already been made and you still feel squeezed it's a lot less plausible to believe that you will grow out of that problem(both because there are fewer evident paths to notable growth; and because feeling poor in a wealthy society is often a good sign that someone who isn't you is good at capturing value; and will probably remain good at that even if more value is unlocked); and if most of the relatively simple, relatively cheap, improvements in things like medical interventions and occupational health and safety standards have already been made it becomes much less evident how your children will do better than you did.
My impression is that, among people who actually reason their way toward parenthood, there's a general desire to see good outcomes for their children. This often involves heavy doses of irrational optimism regardless of location; but there are definitely some contexts where at least expecting your children to have it better than you is within the realm of the plausible; and others where you need to be hitting the copium pretty hard to imagine that they'll beat the odds dramatically enough to do so.