The difference is that it is now possible to make sure that someone is identified by a chip on a card, and s/he could find it impossible to get money, fill a car with petrol (or charge an EV), catch a bus, buy food and anything else that could be made to need a swipe of that card. The implications for social control are enormous.
Yes, there is a lot of information about us stored already, but it is not centralised, and that centralisation is what would concern me. Many of us will be aware of errors in records about us (my medical records have a number of mistakes, for instance) and if important information on centralised cards is wrong that could (and I'm not saying it would) have disastrous consequences for individuals.
There are numerous possible scenarios, but as a hypothetical illustration, suppose the NHS runs out of money, and it is decreed that anyone who can be assumed to have less than 5 years to live can no longer be given medical treatment, as resources are better used on those with a long life ahead of them. A mistake in someone's notes could mean that they are left to die early.
Unlikely? Maybe, but as we have all seen over our lifetimes, times and ways of thinking change.