The printers are deliberately sold at a loss
When your ink dries or runs out, it's often cheaper to purchase a new printer and throw the old one into landfill.
I got very tired of replacing ink cartridges for my HP all-in-one which cost about $50 for a b/w ink cartridge, $70 for a tri-colour ink cartridge, or $90 for a combo set.
So I bought a Brother laser printer for $55 that came with a token toner cartridge that had a smaller capacity than the normal replacement ones, and all the headaches with ink cartridges have gone away.
Agree that those ink cartridges cost next to nothing to make, and it's both a rip-off and environmentally irresponsible by the manufacturers.