I first created that script called m years ago on some Unix boxes that I was using. Could have been HP-UX or other version. And I've used it over the years on many Unix and Linux versions that I worked on. It could be that in some cases, the script is needed due to a tty or TERM or other configuration issue. But I'm pretty sure that I've had the need for it (to remove those control characters) on at least some systems where such config was okay. I know this because, while I do tweak env. var., stty and other settings now and then, I do not always (need to) do so, and have still found control chars [1] in the man output, even when redirecting to file. That is why I created the script, because when working on a C, Python or any other project where I need to read man pages, I often like to redirect the man output to a file (in my ~/man dir) and then read them using vi/vim.

[1] See what I say in that post (about m) about nroff and troff.

Also, I do know about stty, have used it for years, although there is less need for it these days. Used to do a lot of tweaking and experimenting with the erase option (for which, BTW, instead of backspace key in your example, we can also write a literal ^h, i.e. caret, then letter h), intr option, onlcr, ocrnl and others. Used to be good fun and sometimes frustrating too, because docs for this areas were somewhat lacking then.