I'll be honest I haven't fully explored AMIs as a solution but how do you run the AMI in your local dev environment? I can replicate the same K8s with docker images easily in local dev.
that's the crux of the problem. people no longer know, understand or want to know and understand what their software is vs what is around their software. they treat docker and k8s as a way of packaging software and just ignore all the lessons that generations of software engineers have learned when it comes to how to properly manage your dependencies and how to correctly pack your software so that it's resilient and runs anywhere.
we also live in a world that does not appreciate well crafted software and a lot of things are driven by the desire to build a resume. I've maintained code that was decades old and was amazing to work with and was still generating ridiculous amounts of money. I've also worked on code that was just written and used all the possible bells and whistles and development speed grinded to a halt once the it's been around for more than a couple of months.
My worst case scenario is having to work on code where the original developer didn't understand what they were doing and they just wanted to use X. Double the trouble if they didn't master X when the thing was put together.
