Your second paragraph is important here. Flow, TypeScript, and PureScript all have two-way interop with JavaScript code as a design goal. PureScript also has ge

Your second paragraph is important here. Flow, TypeScript, and PureScript all have two-way interop with JavaScript code as a design goal. PureScript also has generating "fast, understandable code" as a design goal. It might be falling short on "fast" here, but it's much more understandable in isolation than the Reason output. This explains pretty much everything the OP notices in the comparison.