My data analysts wet dreams are immutable event logs

They are pure. A promise for great future aggregation. Representing a true picture of the past.

I worked on a project where we integrated Chargebee subscription data. And you get an event log as well. Building up the data model was so much easier and so much more context with that.

Now I hope for every dataset I get from services that there might be an event log as well.

If you are a SaaS think about what people could analyze with the data you are producing for them and then think about event sourcing. It is not that hard to implement but so powerful later.