> The only "negatives" are slippery slope make-believe scenarios not based in reality.
This is an exaggeration. There are countless examples of how this has played out in the past, a quick google search will yield many of them[1][2][3].
The point is that any kind of data collection by a government can and will (eventually) be misused and abused. The UK government is currently abusing its powers to access Facebook and Whatsapp private messaging to arrest regular people for words (i.e not CSAM)[4].
This particular national ID introduction has about as much to do with illegal workers as the Online Safety Act has to do with protecting children.