>I recently wrote a C base class (https://jcristharif.com/quickle/#structs-and-enums) for defining dataclass-like-types that's noticeably faster (~5-10x) to init/copy/serialize/compare than other options (dataclasses, pydantic, namedtuples...)

YouTube also encountered the same problem. Their solution sounds kinda like "never use pickle, because it's slow. Use custom serialization".