I'm not grandparent poster, but depending on who supplies and configures the ID reader, a digital system makes it easier to track people. E.g. if you show your ID at a liquor store, currently the cashier would just check your age and then forget about you. If s/he has a barcode scanner or an Apple ID scanner, then that scanner can log your visits. And your whereabouts can be tracked by following where your ID was scanned throughtout time.

In China, ID cards have RFID and they have to be scanned when entering a train station or airports (or the old town of Lhasa in Tibet), so a future government here might abuse a similar system to track you and maybe harass you by saying "You were in this area yesterday, there was $SOME_BAD_EVENT, what's your alibi?". China also implements long distance travel bans by refusing you entry to the train station/airport, e.g. if you have a bad "social score", which, I imagine would be ripe for abuse in a Trumpian regime. (Although the FBI already abused the no-fly list for the purposes of harassing individuals)