Earlier quoted context omitted.
Doesn’t this just highlight that php development ecosystem doesn’t value quality much? What even is a “file” in context of a web request? What about dependencies or logic defined in other files? This is just bizarre, I can’t see a sane codebase where this would be preferable to going on GitHub and pressing “.”
On the contrary, doesn't it highlight that the PHP development ecosystem values simplicity? That is, a simple application (which this is) can be contained within one file, rather than something requiring several folders, dependencies, and an 'init' command? I don't understand your criticism and I suggest you might not either.
The next on the line is that PHP doesn’t even need anything like version control because you can just copy files over SFTP.
PS: if your project is simple enough to fit in a single file I would argue that most of the time you may use absolutely anything (including a Google Sheet) and you would be equally happy with the results.