That is the same impression I got reading this. I would enthusiastically use any OS-first method if it means one less brittle dependency, but the current usage of environment variable is rather different than what is described in the post.

Where .env files shine is that: - they act as a declaration of expected environment variables, - they are project-scoped, which is one big issue with using "/etc" for example

I personally like to set a .env.example for my collaborators to know what's expected, and I use a .envrc with direnv. And to make it more secure, I always have .envrc in my global gitignore so I can't just forget it.

The drawback is that for any non-interactive run (debugger) I have to manually add each variable each time.