Soda cans and (most) Lego don’t have moving parts and are a lot smaller. If, for example, you want a one-meter wide door to hang exactly horizontally such that

Soda cans and (most) Lego don’t have moving parts and are a lot smaller. If, for example, you want a one-meter wide door to hang exactly horizontally such that the end farthest away from the hinges isn’t more than 10 micron lower than specced, you’d need an angle of less than ±10^-5 radians. For your typical Lego door of 2 cm, that would be ±2×10^-3 radians. Or, as the (current) top comment on https://electrek.co/2023/08/23/elon-musk-lego-cybertruck-quality-leaked-tesla-email/ https://electrek.co/2023/08/23/elon-musk-lego-cybertruck-qua... says: “Golly getting micron accuracy over something a centimeter long strikes me as at least 100 times easier than getting micron accuracy over something several meters long. Is EM learning why cars aren't designed the way they designed the CT? It seems to have evolved from super cheap to make to "the most difficult ever" which is an odd choice for a mass market device” But then, this is how you drive innovation. If somebody is willing to push (and pay) for it, things that are imaginable can become commodity.