Same with digital IDs (for example the EU one), where you'll have to install it to provide a "zero knowledge" proof today, and since you already have everything in your phone, it'll be easy to implement the "real name" policy when registering/commenting/etc.
I'm not aware of any EU project to make a smartphone literally mandatory (instead of just convenient). If they do, I'll buy a separate smartphone just to hold my ID.
https://news.ycombinator.com/item?id=48086778
But you don't have to use that? They still issue ID cards
How will you insert your physical ID card into your computer to prove pornhub you're old enough to jerk off to porn? Or buy a dildo on amazon? Or order booze online? Or in some countries, even just order a set of kitchen knives from ikea?
They already have card readers you use to scan your id on bank websites if that's what you mean