Question on building AMIs

EC2 Image Builder is a fully managed AWS service that helps you to automate the creation, management, and deployment of customized, secure, and up-to-date server images. It is the service to use to build AMI Images : https://docs.aws.amazon.com/imagebuilder/latest/userguide/getting-started-image-builder.html

AWS Systems Manager is the operations hub for your AWS applications and resources and a secure end-to-end management solution for hybrid and multicloud environments that enables secure operations at scale.

I am a bit late for the original poster, but wanted to give some more options in case someone comes across this in the future.

SSM can generate AMI's from existing running instances. Which is a great use case for this service in AWS.

The use case for Image Builder is when you would normally have an image that gets built automatically or on demand without an instance that is currently running. This method allows you to create code to set up and configure what your resulting image should look like. This doesn't require you actually having a manually configured instance to generate an AMI off of. Common cased I have used this is a scheduled job that lines up with MS security release cycle, where it will pull the most recent release and apply all your other software or configurations on and image then place it into your image repository.

On the topic of it being difficult to use, I personally don't find it too challenging, but that is all subjective. I highly recommend looking into Amazon Q, it might just give you the base you need to be very productive with Image Builder. Another option is looking into Hashi Packer, https://developer.hashicorp.com/packer/docs/intro. This is another tool I've become very familiar with over the past several years. If you are comfortable with HCL like Terraform code, then this might be the perfect option for you to create your custom images.