Printers are mostly-mechanical devices, with a little bit of electronics. Most consumer printer brands, though, are designed by computer hardware or consumer electronics companies who don’t know all that much about mechanical engineering. Meanwhile, Brother is a typewriter and sewing machine company—mechanical engineers make up the majority of their engineering competence.

So, IMHO, it’s no surprise that Brother gets design elements correct like “efficient use of toner” and “self-cleaning” and “optimizing for low wear on the print head” that other printer manufacturers struggle with.

(If anything, you’d fear that Brother’s software [e.g. drivers] would suck even worse than everyone else’s; but somehow, it doesn’t. Then again, hardware-headed companies do seem to treat drivers as literal drivers, while software-headed companies seem to treat them as a fat shim that value-adds and makes noise all the time.)