App/mobile and web developers are stretched beyond belief as it comes to skills expected of them. This handbook gives a reasonable overview of the scope of a front-end developer:
https://thoughtworksinc.github.io/front-end-handbook/en/
Yet it's still incomplete, most of the cloud stuff isn't even included.
We're over-asking people. Take Spotify. Has an army of quite decent engineers. They had to actually build a homegrown platform to shield developers from the ops tooling madness. The average developer struggles to understand just git. Even senior ones do.
Front-end developers were a joke 20 years ago. Not taken very serious, not "real" developers. Now it's one of the most complicated programming jobs there are. You have to know...everything.
As for performance, there I do agree that a programmer has a responsibility.