If you diss "american cheese" but endorse "pepper jack" you must be either entirely non-American or just plain ignorant.

Many other countries lack America's "standard of identity" laws that keep cheesse with too much oil or ice cream with too little dairy from being sold as such, and often label the former ultra-cheap food "american cheese" it's not at all what you'll find in the states.

The "American cheese" you can find here is a high-volume, mild, and smooth-melting cheese originally created as a blend of older European cheese recioies, which took off because it did exactly what it was meant to, and pair well with grilled meat patties put on cut buns.

Actual American cheese is perfect for a breakfast sandwhich where you want it to support the other flavors. Other cheeses can be good if that's what you're going for, but so are non-chicken eggs.

("Pepper jack", in contrast, is a simpler cheese meant to be eaten cold as a major flavor on its own. It's absolutely sold in the USA too and can be great on breakfast sandwiches, although I think it works best sliced and paired with cracked and smoked meats.)