I'm from Europe and I have visited the USA many times.
I've primarily visited the West Coast, the Northeast and Southeast of the US.
The toilets may be different in other parts of the US.
Furthermore, my experiences are mainly acquired at hotel toilets and to a certain extent at public toilets.
The standard may be different at private toilets.
American toilets have a very high and thereby wide water level compared to European standards.
The drainage hole is often placed closer to the visitor (seen from standing up),
whereas in Europe the same hole is normally in the rear,
further away from the visitor.
The above have some significant advantages and disadvantages and I will list them as perceived by myself here below.
I believe the intention with the high water level is to as much as possible make sure that there's no need to scrub the toilet innings when finished.
(Very few people would actually do this at a public toilet, both in Europe and in the US.)
In theory, this means the toilet will be cleaner inside for the next visitor.
This problem is partially solved in Europe by using a higher water pressure,
although it's not a 100% watertight (no pun intended) solution.
By keeping the waste in the water,
the smell will be kept at a reasonable level.
If the visitor is sitting down during the session,
the drainage hole can be aimed directly while urinating,
thereby creating fewer splashes on the visitor himself.
For women, this should probably work as expected for all visits
(assuming the average woman sits down during every visit).
For a man standing up while urinating the splashes may become important.
(Very common behavior for men, both the urinating and the standing up while doing it.)
The splashes will often surmount the seat of the toilet,
hitting the visitor himself and even more important,
the back of the toilet seat, the surrounding walls and the floor.
All to the disgust of the next visitor.
Here, I'd like to encourage all men to sit down during all toilet visits in the US,
but being a man myself I realize that other men will find this as inconvenient as I do.
Especially at a public toilet, where the seat may have been thoroughly splashed by a previous visitor.
While he is sitting down over such a high water level it becomes very important for a man not to start thinking of the last time or the next time he spent time with a woman, since this could force the genitals down into the water.
At least if having the habit of leaning forward during the toilet session.
This is especially important closer to the end of the session.
When the excrements fall into the water,
a high level will make it more common for the splashes to reach the rear of the visitor.
This requires the visitor to partially fill the toilet with paper to dampen the splashing.
On a day with a heavy hangover,
the volume let out is often so important that several flushes are required to push the result over the edge down the drain hole.
This requires a relatively high volume of water to be used up.
The high water level may also place the visitor in situations where one or more intermediate flushes are required,
since the result level becomes just too high and standing up during this moment is not an option.
Since the flushing function of the toilet is so unreliable,
the visitor is forced to visually verify the result of the action.
The high water level combined with the large water surface means that the result is more or less diluted in the water,
creating a very unpleasant view.
Unpleasant even if it's the visitor's own result, that is.
Many people prefer to look at it a short while in a consistent form than a long while as a soup of excrements,
urine, paper and water.