Netlify is focused on delivering your frontend and has some light backend features added on (form submission, lambda functions, auth). But you can't run a dynamic application on just netlify, because there is no database. But you might not need a database, which I think is netlify's proposition.
AWS Amplify is focused on providing you a backend (with GraphQL) powered by AWS services (dynamoDB, lambda). You can run an entire dynamic application with just AWS amplify. They also provide frontend hosting now, but that part I haven't used (oops that was your core question sorry). It seems that the CLI tool just configures S3 and CloudFront for you. This is probably much less polished then using netlify.
AWS Amplify is focused on providing you a backend (with GraphQL) powered by AWS services (dynamoDB, lambda). You can run an entire dynamic application with just AWS amplify. They also provide frontend hosting now, but that part I haven't used (oops that was your core question sorry). It seems that the CLI tool just configures S3 and CloudFront for you. This is probably much less polished then using netlify.