Yes, I think one ID, presented only as necessary for those interactions, is enough for them to do their job.

It would be good to clamp down on private companies collecting that data.

There are still a lot of underlying assumptions here worth noting though. You're assuming we must have a government and what it must be able to do, like charge me taxes or gatekeep certain activities behind licensing systems.

I'm not arguing we don't need a government. But to silently take for granted that everything from income taxes to public roads and travel restrictions are a given jumps ahead here.

We could decide, for example, that the government shouldn't be allowed to centralize certain data and remove some of what we expect them to do instead.