Why do parents want to return forms digitally?

I also feel like they don’t send them back digitally when I ask for it and it’s just super frustrating, I’m not saying all parents do this and I understand that there are legitimate reasons for not being able to send it back by word doc or email but why do they also want to send it back hard copy? That’s the whole reason I have an online form is so I don’t have to deal with paper!