The West has largely regulated away airline crashes - the last in the US was in 2009, and it's down 95% in fatalities-per-passenger in the last two decades or so. Stuff like the 1500 hour rule certainly weren't industry initiatives.
That’s hard to assess on an individual level, especially with how rare crashes are today; confidently stating it did nothing is hard to support. On a collective level, the impact of the entire set of regulations on safety is very clear.
> was applied as supposed remedy
No. The post-Buffalo changes included some direct changes like the rules on pilot fatigue. They also included some proactive changes like the 1500 rule.
We don’t have to wait for a crash to make things safer.