That has been exactly my experience, after 5.5 years. My team spends 4 hours in sprint planning every week (there are 9 of us). It is way more important to try to plan out work than it is to actually do the work.
> The bigger problem I have with the company is the types of managers that environment creates. The primary function of a manager at Amazon as far as I can tell is to enforce process and the secondary function is to maximize output of the people reporting to them.
I did burn myself out trying to reduce operational load. I wasn't arguing for it the right way, so I ended up doing it myself. I was able to measure my results, but it didn't even count towards a promo because I didn't "harmonize discordant views"... instead I just did what needed to be done.
Many many folks inside Amazon say it has a startup culture. That is false. Try to find out how many of those folks have actually worked outside Amazon before taking their advice.