> All useEffect and useState does is turn pure functions into mud that reads like a class but drops all the syntactic sugar that makes it readible.

You've nailed it. Their solution to the issues with certain JS OO features was to re-implement Objects minus the features that were a problem, with new syntax. The code's worth a read for anyone who's read how the feature works and is still thinking "no, surely they didn't, it must work some other, magical way".