It's not BS though? That's what companies like Chainalysis professionally. This was covered in graphic detail as to how they caught a pedo ring in Andy Greenberg's book Tracers In The Dark.
Isn't it like claiming that breaking and entering is pointless, as you can always trace the perp through finger prints, unless they happen to wear gloves? Except in this case, most of the criminals operate from outside your jurisdiction as well.