I've done both Drupal and Django work in my career. You are right they were both invented for the full html page generation on every request paradigm. Django'

I've done both Drupal and Django work in my career. You are right they were both invented for the full html page generation on every request paradigm. Django's concepts are much simpler though. Building a headless, API only, back-end feels very natural. You just skip the html templates. You don't even need special libs like Django rest framework. Drupal was invented imho, to solve a much different problem set: the community-built CMS. This is where there are many different class of users going from anonymous to full admins that can perform wide range of write actions. It probably excels in this niche. Django can do it, but using custom code/calls where you'll implement most of the logic. Drupal exposes configurations that you can tweak (and have to manage). You hint on the combinating nature of Drupal modules where every thing can override anything. That is, for me, largely the reason I stopped using Drupal. The Drupal best-practices back in the days (6-7-8), led to awfully unmaintainable code bases for anything remotely complex.