In my state (CA) I would have to actually show up to the DMV in person (normally you can renew online). That's inconvenient enough I'm never going to do it, if they start requiring "real ID" I'll just use my passport.
I always travel with it, personally. It's useful in other ways too, for example people in rural parts of the US can be weird about out-of-state IDs (I look young...).
They can be weird about them but they can’t deny their legitimacy. Americans do have the right to cross state borders. In other countries during Covid, the ability to cross state/regional borders was denied. It made me appreciate the decisions made when founding the country a lot more.
The problem the GP is talking about isn’t in regards to traveling and being denied. That’s not an issue in the US. The issue they would be talking about is what happens IN the state there traveling. For example a bar in Wisconsin could deny you because they don’t believe a Washington DC ID to be real.
If I'm traveling by air, I usually carry my passport as backup ID--especially after somehow losing my license once between the car and the counter at the airport. My Global Entry card is probably sufficient backup to be honest but I also have backup credit cards etc. anyway.
Global entry card is real ID compliant and a suitable backup. If you lose it, there’s not much somebody can do with it. If you lose your passport though, that’s just a more stressful thing to have to resolve
