The "it's for the resume" is a convenient excuse when people ask you why are you spending hundreds of hours on something that seems pointless but is fun to code.
Anecdotally true: when my non-technically-inclined parents ask me why I'm working on my personal projects, I vaguely mumble something about "it'll be good for my resume" and try to change the topic.
I definitely do not think these will benefit my resume in any way.
Yeah exactly when "normal" people ask me why I contribute to open source now I tend to mumble something like that, career professional development blabla. When I was at university I would say something like "learning/practice programming", though back then most of my classmates spent their time playing LOL/DOTA/etc, so if I wanted to program for fun no one would care really.
I definitely do not think these will benefit my resume in any way.