But for most of the world, the cost calculus doesn't work out, because inkjet printers are shitty and break down, and use up their super-expensive color cartridges to print B&W prints. (And laser printers don't work well in humid climates, so good luck using a color laser.)

It's the same reason that in most of the world, you don't see people using those shaving razors with disposable razor-blade cartridges. They're too expensive over time, compared to a straight-razor / safety razor that can be sharpened.

If you only ever need to print, say, five photos in your entire life, it's fine if each one takes a three-hour round-trip walk to town and the equivalent of a day's wages. That'll still be lower TCO than printing every B&W text report you ever need to print on a color inkjet, and so needing to feed it a new yellow cartridge every few months just so it can keep putting microdots on the paper.

Nobody is advocating this for people who can’t afford it. We’re talking about those who can and do need to print often.

I don’t know why we need to argue on about the poorest people who can’t afford it? Sounds like a rhetorical discussion honestly.