Here’s what I mean, I hate carrot cake and spice cake. To me the only reasons those two type of cakes exist is so you’ll have something to put cream cheese frosting on.
(yeah I know some people must like it plain but you get the idea :))
Or to me shrimp taste like nothing. Eating shrimp to me is just an excuse to eat cocktail sauce
What other types of food or drinks or sauces do you think are like that?
When I was younger, crackers were an excuse to eat peanut butter.
Popcorn and lobster exist as transport platforms for melted butter.
Lettuce is an excuse for bleu cheese dressing! (Also, carrots, celery, boring veggies in general.)
Chicken McNuggets are simply a delivery device for Barbecue sauce. (or sweet ‘n’ sour, if you prefer)
Red Velvet cake has cream cheese frosting.
Pancakes are a syrup delivery vessel.
As do snails, or so I’ve been told. I’ll stick with popcorn.
Most pasta sauces are just a coloring for roasted garlic.
Most veggies are just texture added to cheese sauce.
I call these ‘Socially Acceptable Foods’. As in, it’s not socially acceptable to eat X unless it’s eat with Y or in Z manner.
Spaghetti is a socially acceptable way of getting marinara into your mouth.
Lettuce is a socially acceptable way of getting salad dressing into your mouth.
Pancakes are a socially acceptable way of getting syrup into your mouth.
Etc.
A few others have been mentioned.
I use vanilla ice cream as a transport medium for chocolate syrup. I enjoy the vanilla flavor, though…
Mashed potatoes exist only for something on which to put gravy.
And re the OP, what else is tartar sauce for if not for seafood?
Croutons.
Doritos are a salsa vector.
French fries are merely a ketchup delivery device.
Similarly, ice cream is often, for me, the “topping” of the sugar cone (which you can’t otherwise ordinarily find solo).
You haven’t tasted my rosemary-garlic mashers, my friend!
and yep, I call those foods “delivery vehicle foods”- e.g., popcorn is a vehicle to deliver butter and salt.
I’m sorry but lobster is wonderful on it’s own; cooked or raw, I love lobster sashimi. It’s also good with butter, in a bisque, chowder, lobster roll…damn, I’m hungry now!
Well,
Everyone knows the reason spinach dip tastes so good is because of the (cough) goody goodness of the spinach 
Perogies exist solely to sit under sour cream and bacon bits.
Tortilla chips are a guacamole (or salsa) delivery system.
Waffles are the perfect excuse to have ice cream with dinner. I don’t think I’ve ever eaten waffles on their own, but it certainly doesn’t sound very exciting.