The Trendy Perks Employees Don't Want
bbc.com
bbc.com
Sometimes you can tell someone is starting to burn themselves out. I figure it's better to take the (possible) productivity hit from them being out for a week or two versus the long term hits of either them being at work and just performing horribly, or quitting altogether.
If the employees would all be spending money on something, it is better for the company to buy it. That keeps the money from being taxed as personal income.
There may also be a "buy in bulk" advantage.
In locations with poor weather or slow travel or complicated entry/exit procedures, food-related perks also save lots of time. Going out to get something could take a very long time.