I’m not connected with Looker in any way, and they are pretty expensive, but the product is awesome.
Product analytics is one of these complex use-cases. You can't really find a convenient way to run funnel and retention queries in Looker, it only focuses on slicing/dicing the data with their models. Moreover, it has a high learning curve even for the enterprise and there are definitely better ways to approach this problem.
Disclaimer: We're actually working on a LookML alternative based on Jsonnet that will be a better alternative for event modeling. This is how it looks like: https://github.com/rakam-io/recipes. We recently published a VSCode extension for it: https://marketplace.visualstudio.com/items?itemName=rakam.ra...
Take this example: https://github.com/rakam-io/recipes/tree/master/segment/ware... It also makes use of CTEs and lateral joins but it also needs to use a templating engine (Jinja) for data models and Jsonnet for analysis models similar to LookML in order to provide that composability.