If you go to django, flask, laravel, expressjs, hapijs… forum and ask the same question you will get the same answer, the framework of that forum.
So, I try to give an unbiased answer.
In terms of dev time, nothing beat Anvil. Also, you really feel enjoyable when working with Anvil as well, it just works.
But there are few things to be considered. The cloud IDE, which is awesome, is the only place to code. While you can find some way to code without it, it is quite tricky.
The cloud host Anvil is the only PaaS option, and the open source Anvil require sysadmin skills to manage servers, security update… Good news is docker can be used to deploy anvil app.
Furthermore, the open source Anvil doesn’t have much contribution from the community and if there is issue, a pull request need to sign CLA, which is unfortunately not available now.
Furthermore, I am not 100% confident using the open source Anvil in production given the basic issues it has (for example above link). Http-kit, not a production ready server, is used. It seems for dev, not for production.
So using cloud Anvil for production is the only option.
With django, you are free to choose IDE, cloud providers, most importantly, it is battle tested, easy to find jobs, a lot of book and resources to learn.
So, I use Anvil for line of business apps using inside the company firewall and django for critical mission apps.
Final thought, without Anvil, I cannot make tons of amazing apps fast, easy and enjoyable. I really wish that I can use Anvil open source in production.