I am quite a data hoarder, but I take so many screenshots that I'll probably never look at again, and it occurred to me that this might be my generation's "printing emails" thing.
Probably a habit from the dark ages: there is an entire generation (15 years if you were rich in 1998 and poor in 2013) of phones where SMS is the longest freeform text storage available, and only 1 draft can exist at a time, hence the sending.