If there's really demand for some kind of base developer toolkit, why not leave it up for a 3rd party to put together some kind of installer to set it all up for you?
Because a potentially interested 4th grader likely won't ever know such a thing exists.
And even if she did, the teacher likely won't let her download and install it from the internet. But if she asks for permission to run a "Install Command Line Tools" app in /Applications/Utilities/ and check the "Install homebrew" option (or "Install MacPorts" - I really don't care either way... perhaps provide options for both), that's far more likely to get a "yes".
I was only able to learn BASIC and the DOS command prompt because I was in a multi grade classroom, and an older boy (5th grader) whose mother paid for him to have programming lessons taught me on the classroom computer.
The teacher had no clue about any of that... she only knew I started spending “too much time” on the computer.
I know homebrew and iTerm are pretty popular, and that there are other popular options as well. Why not list the top n in each category, in randomized order, with short descriptions and "learn more" links?
Every time I start work on a different Mac, it usually takes me at least 30 minutes to set it up. It would be nice to have a quick button to set up command line tools, iTerm2, homebrew, zsh, and git. Making such setup available from an app would not only speed up the process, it would also gives the dev environment visibility to newcomers and "first class" status from an IT perspective.
PS: also a quake-like mode.
Because iTerm2 is an excellent Mac app? I don't understand your aversion to favoring one tool over another: macOS itself is a tool that I prefer to use over Linux because it's nicer, just as iTerm2 is nicer than Alacritty.
It sounds like what you're really asking for is something like Ninite for mac, which I think frankly is safer to stay as a 3rd party thing, rather than Apple getting super-involved in choices that are going to be very user taste specific.