I’m surprised to see that the OP, as a Django user, does not call out the lack of an out of the box admin tool that’s not there in Phoenix. Django’s admin is amazing and super useful in production. I love phoenix but I miss an admin tool :(
I also would probably include Django Admin in the "app ecosystem" stuff that I do call out. I think if Phoenix had a similar ecosystem, there could easily be something like Django Admin that you could just drop into a project.
The tool Andy uses is called kaffy https://hexdocs.pm/kaffy/0.5.0/readme.html
Something like the Django admin in phoenix would be like taking the actual USP of Django away … and it could even be real-time and collaborative by default :-)
It's all about great abstractions. Django never extracted the table/filter stuff from the admin into a usable stand alone component, and it really shows.
Django admin is stagnant mostly because of lack of uptake in support from companies. Everyone makes their own admin solution rather than collaborating.