A passport has waaaay more personal info than a driver's liscense. That's been part of the move to chipped passports, they can now have basically any biometric data.
Personally I don't see an issue with height, weight, eye color, etc. None of that is exactly a secret, a fairly unobtrusive way to narrow down identification. The only thing I think is iffy is address but that's often out of date anyway. I've also only ever heard of that used to mail lost wallets.
They literally can and do look into your wallet. Opening your pants could interfere with other operations or be unsafe or plain unhelpful (such as with a mutilation). Handing a wallet to an assistant is easier than playing a guessing game.
Knowing generally how your hormones/blood indicators should be balanced can help give an accurate diagnosis. Eg: you're in a coma and a reading outside of the M/F band could catch an early organ failure.