[zeveb]

> You're making the format more verbose and error-prone (someone might easily forget to match a paren), without imposting any additional structure over what is already implied by line breaks.

It's already error-prone (as anyone who's ever incorrectly edited /etc/passwd knows).

Ultimately, structured data (which is pretty much all data) should be edited with structure editors. Good text formats make it easy to write such structure editors.