My life is very, very full. I do not have enough hours in the day, or years in my life, to fulfill all of my obligations and chase all of my dreams and interests. Not even close.
So I buy a lot of clothes from Old Navy, because they offer tall sizes that I need (surprisingly rare) and I honestly just have other things to do with my time. I’m aware there’s a whole world of interesting fashion out there, I just have 100 other things I want/need to spend my time on.
It’s the same with food, a lot of the time. Sometimes I just need a known quantity.
The restaurant chains know this, too. Sure… the commercials are all about satisfying your dopamine needs. But the way they actually run their operations is all about enforcing consistency. A Big Mac is supposed to taste the same everywhere. If you are a McDonalds franchisee, you can pick and choose which McDonalds products and promotions you sell (you can operate without selling french fries, if you’re crazy enough) but you absolutely cannot customize the ones you do sell.
(Yes, there are regional differences between McDonalds in different regions. Even within the US, there are some small differences due to regional suppliers and ingredient price/availability etc. However, these are very small differences and trust me, they really are laser-focused on consistency.)