I hate it. The free drinks on my days off were th biggest incentive for me working there

It's not up to you what others mark out. The food item markout during your shift has nothing to do with Covid; it's been part of the benefits going back to at least when my ex-boyfriend was a partner in 2008. A partner doesn't have to be "in need" to mark out a snack to eat on their break. I mark out cake pops all the time.

To answer the question in your title: it's literally none of your business what your coworkers eat. That's how I feel.