> The short variable names should be clear enough if you understand the purpose of the function.

I shouldn't have to read the function implementation to understand its purpose. Code is buggy! If the function has no name or comment explaining what it's supposed to do, I only have the (often buggy) implementation to go by.

There is no reason to use terse, non-descriptive names in 2021. It's an awful practice that guarantees easy-to-avoid bugs.