The stage 3 noise rules are already in effect in the US. Any civilian ac with an MGTOW greater than 75000 lbs fkying in the US is stage 3 compliant. I seem to recall though that there are a very few exemptions for aircraft operating into MIA. Western Europe is also stage 3 compliant, heading for stage 4. Perhaps also Japan, Australia, and a few others. Some countries comply without any rules though. Fiji comes to mind here.
The day you stop learning is the day you should die.