I guess what's considered food is up to opinion. I've seen countless people using food stamps for energy drinks and chips. While paying cash for their lotto and cigarillos.
How closely do you pay attention to people's payment method? An EBT card looks pretty much like a debit card. I definitely don't pay enough attention to notice what bank the person in front of me in line is using.
I suspect that unless you're working as a cashier, "countless people" is an exaggeration, and even if you are it's likely confirmation bias.