I have a large app in Django at my work. The thing is it doesn't make sense to split this into smaller apps (except for the shopping cart equivalent). It tracks the workflow of our organization, so all queries need to be related from the very start to the very end of the process. (Ok, not all queries, but a lot of them).

Yeah, you wouldn't really want to split a Django app across foreign key relationships unless you want to be doing your joins on the client side with REST API calls, which is more work than letting the ORM do it.

True, but all these installed apps still increase the size of your one project which becomes larger and larger. You can't install it in parts, you can't make any architectural or language changes as it requires a rewrite of the whole project and each new release/ deploy effects the entire codebase.

Microservices doesn't fix everything and you're right about Django encouraging this type of design. Each approach has it's pros and cons.

You can easily have a Django app which calls a micro service.