This thread is talking about a US-based law, so I shared EFF’s perspectives on national IDs in the US. For a more international view, check out Why ID www.accessnow.org/campaign/whyid/ – which they’ve signed along with dozens of other civil society organizations.
It’s true that there are potential upsides of national ID systems as well as downsides. But as that Why ID letter says, “the scalability of digital identity programmes also makes their harms scalable. It is far from being proven that most digital identity programmes have brought additional benefits to users, without placing them at risk.” You’re right that private implementations have similar issues – data brokers and tech companies are as careless with data as government agencies are, and just as eager to abuse people’s privacy. But there are also some big differences: a national ID is mandatory, and the government has much more of an ability to put you in jail or deny you your rights.