Because it makes everything easier seems to be the main reason. A (mostly) crime free society where you don't even need a wallet because the buildings all know

Because it makes everything easier seems to be the main reason. A (mostly) crime free society where you don't even need a wallet because the buildings all know who you are isn't exactly unpleasant as fast as dystopias go. And if you already think the government could oppress you if it wanted to anyway then wanting to add gilding to the cage isn't unreasonable.