What coding style to use in Django Wagtail?

Question

Django

Hello!
I am studying CMS Wagtail based on Django and noticed such a feature, all code is located in database model files, from creating tables to data fetching and routing. The next question is how much is right? After all, in the "classic" Django application, the MVC principle is the basis, the models are separate, the routes are separate, the views are also separate.
Share your experience on how it would be more correct to write applications and how do you do it ?!