If you already are experienced with Node & Java, I doubt it is worthwhile for you. Just keep gaining experience there, I don't see Django overtaking any market anytime soon. It's a niche compared to others, but there is a lot of work in building microservices and API's. As a junior & freelancer, there is no shortage of work for me. Sectors range from API's to pure backend service & DevOps automation. Purely backend jobs.

With .NET and React in your toolbelt, you already got easy to deploy, powerful and job market. What else do you want? :P

Could always try out F# if you think the grass is greener out there.