I encountered the same sort of problems at amazon, I felt like it was because leadership didn't incentivize those optimizations to be made across the org. We'd identify some team that was the only one that could help us with something and nobody would lift a finger for us. Teams who were on the hook would ship us incomplete and untested APIs claiming they were done in order to work on other stuff. Managers didn't want to bring it up with other teams because of political ramifications.