The fact that you do not physically possess your social security card does not mean that the federal government did not issue you one. So you Have it, you simply don’t have it on you.

You haven’t needed it since it’s such a bad ID that if you know the number you often don’t need to possess the paper.

This is like saying I drive without taking my drivers license with me.

No. I'm not sure what the circumstances would be where I would have to present an actual social security card. Certainly never encountered one. Whereas it's easy to imagine circumstances where not having a driver's license on me could cause issues--even if it might technically not be required.

I used to use mine (plus my driver’s license) as my I-9 employment verification documents. Driver’s license for identity, SSN card for right to work.

You can also use a birth certificate to establish right to work, so yeah it wouldn’t be required.

Of course now I just use my passport, but like many Americans I didn’t have one for many years.

Fair enough. Not sure why I even carried my SSN card at that point. I've had a passport since I was around two years old.

You don’t need it because it’s so weak that people will accept that knowing the number is the same as having it.