Amplify is 2 tools so answer is slightly confusing, amplify is both a
• a set of sdk’s for interacting with AWS at a slightly higher level than the aws-sdk, this can be used with SST and is quite useful for things like cognito
• A CLI tool for deploying resources to aws
The CLI tool is easier to use and more prescriptive about a bunch of things than SST this makes certain things easier and faster to get set up, however it also has a bunch of drawbacks. The biggest is that its not good for team projects its very easy to have conflicts if you are both working on the same project, the other is that its not infrastructure as code its just an automation CLI that outputs computer generated infrastructure as code, This means you often don’t understand what you are doing.