This is mostly just a philosophical question.
I am looking at integrating GTM and implementing Enhanced ecommerce tracking with it, and the more I look at it, the more I feel like these two are fighting each other.
GTM seems to encourage a seperation of concerns from the web app, where the app exposes generic data points to the data layer and a "Markerter" or similar sets up tags in GTM using those variables.
However, the recommended way to implement Enhanced ecommerce is to add very specific data directly into the data layer, and just tick a box in GTM. This means that the data layer is no longer generic, and you cannot implement Enhanced ecommerce without changes to your backend or "without IT dept support" as GTM likes to advertise itself.
Am I missing something or is google not eating its own dog food here??