there's a difference between "the police can request this information from an individual" and "this information will be automatically gathered from everyone at all times and stored by the state". for one, there are circumstances in which the police are allowed to request that information and you can say "no", and there are also practical limits to the number of police that can be out requesting. The central equivalence you're trying to draw here is simply false.

Especially when they drop NFC into it and put up observation posts around the city

No, police cannot.

The government is pushing Digital IDs on rubbish claims (obviously won't do anything about illegal immigration). Everyone can see that.

So what does this mean about their actual aims?

They can certainly ask, but at the moment can they jail you simply for not answering?

yes. yes they can.

They'll invoke one of the more ambiguous sections, it's usually the anti-terrorism one, but sometimes is the anti-drugs one (i can't remember the numbers), and they'll detain then arrest you and haul you to the police station.

You can complain later, and maybe get some pounds out of it, but make no mistake: if the uk police wants you identified, they will identify you.