This is called a notary public. Its a routine requirement with immigration documents. .They can also certify copies as true.
In UK for sone reason it costs over £100, and noone uses them, but in eastern europe its common and notarising documents is like €5 - they just check you identity
They may give you the run around saying “the notary isn’t in today”, options here are ask them to tell you which branch you could visit where the notary is available, or what day and time is best that you’ll surely catch the notary. They will be uncomfortable about this pressuring but they are required to provide this service.
If you need to sign something then you sign it with your ID. Same ID can get you into your accounts online.
No different to Estonia’s digital ID scheme a decade ago.
I think the real reason was that it sounded like it’d cost £60 (or close to that) per ID, which is pretty damn expensive when it’s mandatory. Most of that money would have been sunk into the black hole that is the IT consultancy industry in the UK, with literally no guarantee of a working solution being built.
Usually when you travel you keep at least one form of ID on you - probably not your passport but a local ID or driving license or something.
You may assume anything you like indeed.
Due to the track record of the RIC, the British police prior to independence (and something that continued in NI until the 90s with the RUCs to keep the idea fresh), there is decently strong opposition to ID cards on the idea that police could demand them to harass people. It's also why most Gardai (Irish police officers) are unarmed, though I think the rising perception of petty crime in Dublin has swung the pendulum somewhat on that topic.
H.Can you use them at home to sign lime a rent agreeement or something? What equipment do you use them with?
Some JPs take payment in the form of a box of beer or some small thing like that.