The problem is it's cross-border. Domestic law enforcement will almost always run into dead ends, maybe they'll catch some money mule that got conned into the job, but that's it.
The real dent would be to get India (for US scammers) and Turkey (for German scammers) to cooperate, the way to do it would be to threaten devastating sanctions ("clean up your scammer scenes, or else"), but that cannot be done as it is important for geopolitical reasons to appease India (a significant portion of the world's pharmaceutical base compounds originate from there, not to mention the Ukraine conflict) and Turkey (same reason, Ukraine conflict + about 2 million Syrian refugees that Erdogan already abused as a political weapon once).
The real dent would be to get India (for US scammers) and Turkey (for German scammers) to cooperate, the way to do it would be to threaten devastating sanctions ("clean up your scammer scenes, or else"), but that cannot be done as it is important for geopolitical reasons to appease India (a significant portion of the world's pharmaceutical base compounds originate from there, not to mention the Ukraine conflict) and Turkey (same reason, Ukraine conflict + about 2 million Syrian refugees that Erdogan already abused as a political weapon once).