How if you rely e.g. on CASCADE and foreign keys, which are not on by default kn SQLite? I think then things start getting complicated and testing that layer gets difficult.
Django allows for the common use cases for that to be abstracted out. So the SQLite version will do things manually, while PostgreSQL can use the database feature.
That's the reason to use an ORM. It abstracts away things like that.
How if you rely e.g. on CASCADE and foreign keys, which are not on by default kn SQLite? I think then things start getting complicated and testing that layer gets difficult.