You could probably leverage 2-3 years at Amazon to a much better job somewhere else as a cloud guy. It is all about credentialling and other signalling, to get your foot in the door. Remember the only purpose of a CV is to secure an interview.
Well, it depends. Any F500 hiring manager would pay top dollar for an ex-Amazon guy to work on their cloud effort, maybe not as much as a FANG but 9-5 with decent job security. If you were looking to settle down somewhere long-term it might be worth the hit.