Is this a claim that people do not indent in other languages and leave it to the dev environment? Yes, those languages don't rely on indentation but people do still manually indent or rely on their environment to indent it for them to make the code remotely readable. I for one cannot read Java without it also being indented correctly.
> This frees the developer from the job of manually formatting their code like some sort of caveman.
I honestly don't understand this part. What tools are you using that don't do indentation for you? Emacs and vim extensions, vscode, Pycharm, atom...all of them have very intuitive indentation for when you type. The most you have to do is hit backspace after finishing a block.
> Especially considering it's so easy to fix Python the language so that indentation becomes unambiguous: add an "end" statement for each deindent (aka closing brace).
As someone with a lot of Ruby experience, the "end" is absolutely not more clear than indentation. There's a reason environments highlight do-end pairs together: because it's hard to know which ones match which.