The only comparison I can do is that Django Admin is built-in out of the box, so I use it on every Django project. Rails/Active Admin is not built-in out of the box so I've never used it and always built my own admin page.
It's super weird because Rails is known for convention over configuration and includes default packages for basically everything you might need EXCEPT auth and admin. Meanwhile Django removes a lot of the magic of Rails and lets you do it yourself, except for bundling auth and admin into the core product.
I used ActiveAdmin a lot when I started and it always gave me a headache. From what I have seen of Django Admin (admittedly not a lot) it looks very similar?
I have found that at least for my users, admin type functionality and views generally require a lot of custom work that is not easily turned into convention. About 4 years ago I stopped using Active Admin completely and just started using Ransack + Kaminari gems on their own. I have been a much happier with the way that pattern has worked out.
It really depends on the specific use case. It's possible to arrive at a point where you'd get more mileage out of using something like react-admin and custom API views. But, until you arrive at that point, something like Django Admin or Active Admin can get you quite far.
It's super weird because Rails is known for convention over configuration and includes default packages for basically everything you might need EXCEPT auth and admin. Meanwhile Django removes a lot of the magic of Rails and lets you do it yourself, except for bundling auth and admin into the core product.