My point is that those transpiled languages aren't that stymied. You can use them without a lot of problems, and they're being left on the bench for reasons other than their feature set.

Companies generally choose JavaScript because there are lots of developers to choose from, it runs everywhere and the ecosystem is huge.

Engineers choose something like PureScript as it's not a 'blub' language and people think that by choosing it they will be able to hire (or be seen as) "math geniuses". I'm sure the feature set is important, but it's not enough to unseat a language with the previously described properties.