I think that's a fair point, but the analogizing goes both ways: yes, your phone is generating a lot of information about you that simply wouldn't have existed in the pre-Internet era, but at the same time a lot of information that would have existed in that earlier era is now inaccessible by default, without any effort on your part.
I think the government is on the wrong side of this issue, but I don't think they're making the broad "going dark" concern up. I think technologists need to engage more fully with the law enforcement concerns here rather than dismissing them.
There are already a lot a more sources of information today (beside encrypted nessages) than there was in the pre internet era. At that time you simply called from a public phone (for example), even less trackable. Not to mention all the nowadays technology that ease remote tracking of any sort (micro sensors, cameras etc etc). So no, to me it does not go both ways
I think the government is on the wrong side of this issue, but I don't think they're making the broad "going dark" concern up. I think technologists need to engage more fully with the law enforcement concerns here rather than dismissing them.