The only downside to Phoenix compared to other frameworks is that you’ll have to build a lot of things yourself – or, if you don’t build them, you will definitely have to properly assemble the already-built pieces together.
F.ex. Rails and Flask have ready-made authentication solutions that you more or less simply include in your project, while Elixir’s Pow library you have to specifically install inside your app and configure here and there. And it allows a lot of customisability.
Elixir and Phoenix are amazing and I never regretted learning both. They made me much more productive than when I worked with Rails and Java before that.
But there are people who expect everything to just work out of the box with minimal effort from their side. Those people usually get disappointed by Phoenix.
