The Laffer curve is a statistical tool. Not everyone who gets taxed at 70% will drop out of the economy. Some will continue to work at even 95% taxation. Others will slow down at 40%. The 70% figure seems to be where enough “high achievers” drop out of the economy to hurt it.
As for Mr. Bezos, he also has the tools of shell companies and offshore tax havens to reduce his percentage of taxes probably lower than his low-paid employees. He is still an active player in the economy. He’s a good sign the Laffer seems to be working.