From Talmud Brachot 40a, we learn that if one accidentally said "Shehakol" as the before blessing instead of a food's proper blessing, this is fine, and he doesn't need to repeat the correct blessing.
I'm curious as to why "shehakol" was chosen as the "overall" blessing and not Borei minei mezonot which means "Who creates different types of foods (or sustenance)." This blessing mentions the term "food" whereas "shehakol" does not.
It seems that at some point or for some reason, "mezonot" was used to refer only to foods made from one of the 5 grains. We can also question, likewise, why mezonot which has no mention specifically of "grain-type" foods was made as the bracha specifically for these types of foods?
For that matter, if "mezonot" means "food", then why not use this bracha and not even need the "shehakol" bracha to be created at all?