You can be unproductive by daydreaming.
You can be unproductive by taking a nap.
You can be unproductive by eating a bunch of snacks and watching videos.
You can be unproductive by being bored, which... might not sound fun, but that's the time when I do some of my best cogitation. And I find myself bored less and less these days.
Or, I dunno, maybe you think all of those things are productivity, too, in which case---what are we even talking about?
You should do things because you want to do them. And if you want to do nothing, you should do that, too.