GOOD: finally figured out why/when I might want to use the Python `cattrs` library (tl;dr, when you're using `attrs` and want to do vaguely Pydantic-like things when serializing/deserializing to/from json/yaml/etc)

BAD: now I'm going to be constantly second-guessing the dayjob's use of Pydantic with "would this work better if it was attrs+cattrs?" (see e.g. "Why cattrs?" assertions about serde-type activities belonging at program edge, not core: https://catt.rs/en/stable/why.html)