It’s not a cost-cutting measure to save on plastic
Whenever you have cause to venture out to the loo you might notice that your toilet seat isn’t always the same shape.
It’s definitely not going to be your main concern as you’ll primarily be focused upon the evacuation of bodily waste from your bowels, but as you expel the pee and poo into the toilet bowl you might give the shape of the seat a passing consideration.

Most toilet seats you’ll encounter in your lifetime will be ovular, but occasionally your throne seat will have a U-shape with an open front.
You might also notice that toilets you encounter in people’s homes tend to have the complete oval, while the open front is normally seen in public loos.
If you’re across the pond in the US of A you might notice that open front toilet seats are even more prominent in public places, and it’s not all about cheaping out on the plastic.
Over in the US in 1955 the American Standard National Plumbing Code (ASNPC) declared the codes that public toilets would have to abide by when providing seats.

They said: “Water closets shall be equipped with seats of smooth non-absorbent material.