Depends on the implementation. E.g. Javas HashSets include has the same performance profile as a Map lookup. Its still not particularly performant with large da

Depends on the implementation. E.g. Javas HashSets include has the same performance profile as a Map lookup. Its still not particularly performant with large datasets, but significantly less abysmal then a regular JS .includes(). I just didn't want to explore the example to such a depth, as it felt irrelevant to me at the time of writing.