How is a fax any different from a scanned and emailed document?
Scanning a bunch of docs is a pain. 1 page is fine, but otherwise, just get it sent. (BTW, just whipping out a pen and writing on a paper scrap is mostly easier than button-button-button-button-button....as is talking directly to someone on an actual phone rather than button-button-button-button-button...)
Scanning means 2 basic steps - scan the doc (with all PITA rituals of did it work, size OK, etc), THEN e-mail that file.
Have multiple pages for most of us, that becomes painful. It’s kind of ROI.