I think Django embraces the Python mentality of "batteries included" and Javascript frameworks follow the Node mentality of reusability and fragmentation. So in my mind it makes sense there's no Django for Javascript.

Also Django was created at a time when AJAX was at its infancy. Most apps needed to generate HTML and the server side had to include templates, routing, authentication, etc...

More modern applications rely a lot more on client side code for routing, and HTML generation and the backend is mostly an API for a non-relational database. Plus a lot of other services for random things like Auth, caching, etc... To the point a lot just opt to go serverless and connect directly to a Firebase for storage for instance.

Django doesn't feel so at home in those "newer style" apps. Most features go unused and the ones you want don't have great support and you have to rely on other tools such as django-rest-framework. If you want to use a NoSQL database, then the nice ORM goes out of the window and you usually lose the Admin interface.

So in other words I think a Javascript Django would have very low usage, because people just don't build apps like that anymore. People prefer light backends reliance on external services and more specialized data storage options. So they want something that is lighter, easier to deploy and scale.

The only reason I still would use Django today is the amazing Admin interface you get in exchange for using its ORM with a relational database.