Not so Simple
Unfortunately, I think the issue is over-simplified into x is better than y, or y country is better than z.
The fatigue issue has become corrupted by self-interest, both of pilots and airline management. Things might have swung in the right direction in the US for some carriers, but it is only a recent change based on costly lessons from crashes such as Colgan Air and UPS. If you read between the lines fatigue should have been the primary contributing factor. Unfortunately in Europe things are moving the other way. Lobbying by airlines has greatly reduced the margins that used to exist.
CAP-371 was firmly based on scientific studies by Qinetiq. EASA now leaves us with a compromise that is to be reviewed based on reports over the course of 2 years. Add to this a lot of self interest. For example, does the commuting culture contribute to fatigue? As is common in the US and with LOCO’s in Europe. Would someone who just positioned in at the last minute for personal reasons be less likely to call fatigued?
Also due to the static pay and increase in productivity since the year 2000, flight crews are now pushed to breaking point. You are either left with your life completely revolving around your job, or feeling fatigued. Of course there are some exceptions such as certain flag carriers, but these are few and far between.
The other difficulty with fatigue is properly diagnosing it. For other issues such as Alcohol we can easily set rules to say that someone can only drink so and so much before a flight, but to tangibly measure fatigue is elusive. It is insidious and creeping. Small things such as lack of short term memory, lack of focus and concentration, and missing small things are the first signs to show. However the company will just say, it is within the FTL scheme to it is legal.
There is a long way to go everywhere with regard to putting fatigue into check, everywhere in the world.