It is clear that you were brought up on "the wrong side of the culinary tracks".
First of all, cheddar and "Swiss cheese" ain't the same things. Cheddar at its best, either from the UK or from the USA is a well aged cheese, generally orange in color, firmimg up as it ages and packed with rich flavor. True, the cheddar that one finds pre-sliced and packaged in plastic (with little pieces of white paper between the slices) is abysmal stuff and to be avoided at all cost but true cheddar is indeed a gift from the gods.
What Americans call "Swiss cheese" is a take off on either Emmenthal or Gruyere cheeses, both of which at their best are also exquisite, either on their own or in combination on sandwiches (ham and cheese sandwiches on an Italian bread with mustard, lettuce and tomato can be superb.
To complicate things even further much of what Americans call "American cheese", "Cheddar" or "Swiss cheese" is actually processed cheese.....cheese loaded with salt, preservatives, water and with any resemblance to true cheese long destroyed.
Tell me where you live and I will tell you where to purchase some real Cheddar, Emmenthal and Gruyere. And I shall make you a happy person. I promise.