I would hazard a guess that the people on your former team at Prime were "managed out" after strongly opposing the dark patterns that product teams and execs demanded they implement. Would be cool to hear from others with actual knowledge of the situation on the specifics of how this state of affairs came to be.
An aside:
I am strongly considering canceling my Prime membership. I don't need 2 day delivery on anything that I order from them. In addition, Prime memberships have increased in price, and I don't use any of the other benefits that Prime offers. Throw in the fact that 1) prices for everything have increased to the point where it's often easier and cheaper for me to go to my local big box store that starts with W or C, and buy the same thing and get it same-day, and 2) there are so many knockoff and bogus sellers on Amazon now, and Amazon does not do a great job at enforcing their policies and removing them.