What do you use signatures for if not reminding students to get their parent signature?

Our school is (supposed to be) 1:1 and we use Google Classroom. I’m changing up all my assignments for next year and I’m wondering, what do you use a signature for then? There are endless threads about students getting their parents to sign or initial or put their finger print on it. I’m ditching all that (because of Google Classroom) and I’m wondering what else you use signatures for.