The official Amazon API has a number of restrictions around its usage. Mainly, they require that you advertise Amazon products to use their API.
This means to build a SAAS or target B2B applications you can't use the official API, or risk getting your account restricted.
This is what happened to me, so I built this GraphQL API :)
Show HN: Canopy API – A Modern GraphQL API for Amazon Data
canopyapi.co