Nothing about the word "national" implies "mandatory". There are other countries with national IDs which are not mandatory.

https://en.wikipedia.org/wiki/List_of_national_identity_card...

For example:

https://en.wikipedia.org/wiki/National_identity_card_(France...

Not if you want to travel by air.

That's an abusive attempt at a workaround by the Fed to make it mandatory.

Thankfully, it appears my state will continue to offer the same IDs it always has in addition to the "enhanced" ones. I suppose I'll have to start using my passport for domestic flights in 2021.

I'm well aware of this. But nobody is forced to fly in America.