You seem to have a very AWS focused perspective. Your statements about containers and serverless are not true when you look at the spectrum of products out there and dig into details.

I wouldn't build a serverless framework or platform. There are cloud provider options and kubernetes based options. People use serverless when it makes sense, but it's not going to become the dominant way people deploy software. Not sure what you mean by "tool"?

Why do you care about what database users have when thinking about building a serverless tool?