My theory is that the food tasted less flavorful, so people compensated by adding their own.
I don't eat a lot of junk food, but for a long time after the Obama administration, when I did partake, often my immediate reaction was "Wow. These aren't as tasty as I remember."
/I'm looking at you, Cool Ranch Doritos.
https://jamanetwork.com/journals/jama/fullarticle/2768807?re...
https://www.vox.com/2016/10/3/12866484/michelle-obama-childh...
in all likelihood it's just enshittification, as those big corps make more slop for the plebs to eat in the cheapest way possible