Places that need to produce multipart forms, for legal reasons or because their workflow is still based on paper. Every delivery I’ve ever taken of furniture or appliances, I’ve been asked to sign a “I have received this thing from you” form in duplicate or triplicate, printed on a dot matrix printer. Every bank I have ever dealt with, ditto. Endless examples from bureaucratic institutions.
Besides multpart forms, they are still the cheapest way to print, as long as you don’t care about the output looking pretty. So they get used for bank receipts and such like as well.
The thing is, many modern dot matrix printers have scads of soundproofing built into the printer case (and/or are kept inside a soundproof cubby), so instead of “screech! Screech!,” all you hear is “whirr whirr”, which can fool you into thinking it’s not a dot matrix being used… until you see the printed output.
