There is a “better” painkiller than both Tylenol and Ibuprofen (Metamizol), but it has been forbidden on the US based on a study attributing strong side-effects to it, despite it being freely available over the counter on multiple countries for decades without issue.
If this study is true, it should be easy to compare prevalence of autism on these countries that don’t rely on Tylenol.
It's not just banned in the US; it's also banned in France, the UK, Norway, Sweden, Iran, and Canada among others. It is legal OTC in India, the former USSR, China, Mexico, and most of South and Central America. It is the most popular prescribed pain reliever in Germany and the most popular OTC drug in Brazil. It is popular in Spain as well.
Metamizole is actually a very interesting case, to me, as the associated risk is quite strange. It is legal and popular OTC for the majority of the world population; in the countries where it is legal, there are few deaths from the native population. Among tourists who consume it, however, mortality is unusually high. The Spanish health ministry declared in 2018 that it should not be used in the "floating population", including tourists. There may be a genetic component involving Anglo-Saxons. See: https://www.theguardian.com/science/2023/nov/26/painkiller-b...
Here's a map of its availability: https://commons.wikimedia.org/wiki/File:Metamizole_(Dipyrone...
There's far more than one study now linking metamizole to agranulocytosis.