(FWIW: I suspect there are more than a few old industrial control systems and such out there that are still running DOS, just because of an "if it ain't broke, don't fix it" attitude)
My brother is in manufacturing. DOS is everywhere. Older things too (PDP-11? DG Nova? Seen both, semi-recently). Not just because "ain't broke, don't fix", but because when you have a cloth dying machine or brick forming machine you spent >US$5M for, that is often a bespoke install for your plant, you don't replace it because some guy who prolly slings Javascript all day sez "DOS is oooold, boomer".
My brother is in manufacturing. DOS is everywhere. Older things too (PDP-11? DG Nova? Seen both, semi-recently). Not just because "ain't broke, don't fix", but because when you have a cloth dying machine or brick forming machine you spent >US$5M for, that is often a bespoke install for your plant, you don't replace it because some guy who prolly slings Javascript all day sez "DOS is oooold, boomer".