You gave me bullshit and I provided facts refuting your bullshit.
Here is the I9 form. The new employee simply states under oath they are a US Citizen.
It only requires a drivers license and a social security card when filled out by the employer. Non-citizens can have social security numbers so there is no proof of citizenship given to the employer.
Your claim that you have to prove citizenship to get a job is bullshit. You only have to sign an affidavit you are a citizen the same way you have to currently sign an affidavit when registering to vote.
It is interesting that SSA tells me I don't need a passport or a birth certificate to apply for SS. I wasn't required to provide them when I applied. And yet here you are making a claim that is directly contradicted by the official application process and claiming you know more. You CAN use a birth certificate or passport but you are NOT required to do so.
https://www.ssa.gov/help/iClaim_poa.html