For example, how is Google's "Jules" different than JetBrains' "Junie" as they both sort of read the same (and based on my experience with Junie, Jules seems to offer a similar experience) https://www.jetbrains.com/junie/
The loop is: it identifies which files need to change, creates an action plan, then proceeds with a prompt per file for codegen.
In my experience, the parts up to the codegen are how these tools differ, with Junie being insanely good at identifying which parts of a codebase need change (at least for Java, on a ~250k loc project that I tried it on).
But the actual codegen part is as horrible as when you do it yourself.
Of course I'm not talking about hello world usages of codegen.
I suppose these tools would allow moving the goalpost a bit further down the line for small "from scratch" ideas, compared to not using them.