The reason American toilet stalls have a gap between the floor and the wall is to make cleaning easier.
There's also a gap between the door and jamb is needed because it offers clearance for the hinge and door swing component.
The reason American toilets have a gap in the toilet seat is to make it easier for women to wipe after peeing without needing to stand up.
The reason Italian bathrooms have 2 toilets is because one is a bidet and the other one is a toilet.
The bidet is used for washing your butt after you poop in the main toilet.
In away the bidet is a kind of toilet but only for washing pee and poop off of you after you use the main toilet for pooping.
The reason Italy doesn't have toilet seats in many public restrooms is because of the toilet seats being broken by people squatting on the toilet seats to poop.
The toilets in Italy did used to have toilet seats but over time the toilets seats would get broken because people in Italy would stand on the toilet seats so they could squat to poop.
So as a result the toilet seats would get broken and so people in Italy decided to stop using toilet seats.
Many areas of Europe may have public toilets without seats.
France, Italy, and Greece are three countries known for toilets without seats.
It has nothing to do with the operation of the toilet itself.
Instead, some toilets have had their seats removed due to maintenance issues.
France and Italy also have some squat toilets remaining in old buildings and public toilets because they used to be the norm there in the early 20th century.
In BMW Welt in Munich, the public restrooms have some stalls with squat toilets.
Squatting is the more natural way to poop instead of sitting.
For example kids who are in diapers and are not potty trained will often squat down somewhere or at least partially squat down to poop.
Squatting makes it easier for the poop to come out than it does to sit.