You are applying one size fit’s all and that is not true in many states. Maybe in Ca. In other states you have to prove a physical address. You have to prove a rent receipt, utility bill, long term motel receipt, or a slip from a homeless shelter address to be eligible. And this is my point. It is not a universal situation. It is solely dependent on the state you live in.
https://www.ssa.gov/pubs/EN-05-10101.pdf
If you are experiencing homelessness, you can still get
SNAP benefits even if you do not have an address,
a place to stay, or a place to cook meals.
Is SSA.gov good enough proof for you?