I hear you. I’ve been asked a number of times to build a sample application, but I have resisted so many times, because I just don’t think it would actually explain some of the points you make.
The data point is key. My experience with scaling serverless was very clearly that you write data into one data store, but read from somewhere else. That allows you to optimise data stores for write and optimise them for read. It’s a big paradigm shift for many who have never done anything outside of the SQL world and some who’ve done some NoSQL too.
Part of what I’m trying to do is to avoid the “it’s simple to build serverless” with a “here’s some things you should know before you get started” type things. Hopefully it’s a starting point!