Broadly you have a point. In this case I would expect a Rust-based Python linter to run significantly faster than one writen in Python itself (e.g., pylint).

ruff is not new. It's also truly really fast. On an as-yet un-ruff'ed 32k SLOC python package it returns in 158ms finding 2k errors. Having it fix errors is also very fast.

What's really tiring is reading such facile "critiques", especially when they are not even applicable.

Compare it to some of the other options in that space and you'll see why that was a selling point.