>Ibuprofen is anti-inflammatory medication.

And an acetaminophen tablet is a painkiller. While your statement is in fact true, ibuprofen is still a better choice for a fever. The latter is also generally considered a safer alternative, especially in long-term use — even though alternating the two would be ideal.

Acetaminophen is actually a pretty dangerous drug that is pretty easy to overdose on. It’s been said if it were discovered today it would be a prescription drug.

On top of that numerous recent studies have shown many potential problems.

https://www.webmd.com/drug-medication/news/20150302/does-lon...

> Heavy use of acetaminophen is associated with kidney disease and bleeding in the digestive tract, the paper reports. The medication also has been linked to increased risk of heart attack, stroke and high blood pressure, the study authors noted.

> One cited study even showed that overuse of acetaminophen can increase a person's risk of early death as much as 60 percent, the study authors found.

how true would rate wikipedia's current claim that "how it works is not entirely clear" ?

If you have a fever, why not both (as long as you’re hydrated)?