Something like 10% of SNAP benefits go towards purchases of soda pop and other sugary drinks made by PepsiCo/etc.
But the "soda" category these days is also pretty overloaded: full sugar coke vs Coke zero is a very different calory intake.
That's why SNAP money is restricted to particular categories. So caring about how it's spent is already a foregone conclusion, and rightly so.
If someone wants to spend money however they like, they'll have to earn it themselves. Even inherited money carries a sense of obligation to honor the family with how it's used (like not blowing it all in a week of lavish partying in Vegas, as an extreme example).