It is easily gamed and it requires providing documents, usually these are photos or reproductions of passports which are provided digitally and can be easily altered. And employers don't have the skill or ability to detect them, or often the will to investigate.. by having copies of the documents they can show they did what was required and claim to have been misled and they are the victims, so no prosecution or fines.
That's not how it works and it is not easily gamed.
You must provide your original passport, not a copy. And if you are a foreigner you must also provide a "share code" that allows the employer to go to the Home Office's website and check you details, including picture, and entitlement to live/work/study in the country.
Again, if some employers are unscrupulous, or just plain idiots, ID cards won't change that.
> by having copies of the documents they can show they did what was required and claim to have been misled and they are the victims, so no prosecution or fines.
