The word simple should never be in close proximity to Kubernetes. They're mutually exclusive when you consider the total cost of devops, maintenance, debugging, and all the time you'll inevitably waste on things that have nothing to do with your business' unique value proposition.
With that being said, adaptjs looks interesting for more complex scenarios that actually warrant such complexity. My only gripe is that 95% of companies that use stuff like this use it to satisfy developer's desires as opposed to satisfying a real product / business need.
I do agree that Kubernetes is too complicated an low-level for most needs, especially for small projects. However,
my experience is that while most apps start out really simple, if they are even modestly successful, they'll eventually need something not supported by whatever PaaS/Serverless/whatever they've chosen for deployment.
The hope with Adapt is that you start out with a really simple interface that looks like a PaaS/Serverless (Heroku, Zeit, adapt new/run etc.) but can be tweaked over time without having to throw out everything that was great about the PaaS. And by no means is Adapt limited to Kubernetes, it's just what is there now.
I think that a simple interface to something like Fargate/ECS with Adapt would be pretty nice as it removes the K8s complexity but handles all the container build/repo management stuff for you.
With that being said, adaptjs looks interesting for more complex scenarios that actually warrant such complexity. My only gripe is that 95% of companies that use stuff like this use it to satisfy developer's desires as opposed to satisfying a real product / business need.