I wouldn't say it's Biden's fault but his policies certainly didn't help. The costs for food and labor shot up during his few years in office with no remedy in sight.
The quality of BK has been sinking for the past few years. Only us older folks remember what a real Whopper tasted like. If people today could have a Whopper like when they first came out and have a Whopper today, it's like two totally different burgers. What I wouldn't pay for an original Whopper today, but most people wouldn't. That's why they kept using less and less quality of ingredients.