I'm not on any Amazon team, but I actually reduced my development efforts on our last startup for these exact reasons.
We had invested 10 years of development time, and millions of dollars into internal software systems that we used to start and grow a 4x Inc 5000 ecommerce business.
A number of our clients and contacts in our network had been inquiring about our systems for years, so we piloted a multi tenant MVP for Fortune 500 type companies with tight ISO requirements to run their own 3rd party FBA operation internally.
We hit a number of unresolved bugs and issues within their api, and found a number of undocumented features.
It got to the point that a number of bugs were blocking our innovation, so we flew out to Seattle to meet with the Seller Api Teams as a final hail mary.
I believe it was at the top of the "closed for private Amazon event" Space Needle that my co-founder and I realized that they really didn't actually care about fixing our issues, and that our destiny would be in their hands if we continued investing into it :(
The startup and app still exists, and it still has daily active users and sign ups... But major innovation has paused for now, and I've put my focus into another idea for now.