All engineering requires trade offs, in this case you’re trading productivity in one area vs flexibility.
What use is "productivity" without a performing product?
Is it a high-value feature to the end users? Then absolutely, you're correct.
Anyway, in my experience, most good PM and designers want an understanding as towards the amount of effort their features and designs mean for engineers. So if you aren't providing them that feedback, and letting them to factor that into their process, you're doing them a disservice.
I mean, I can double my native productivity that way too !
If you need an app on both Android and iOS quickly, have low quality concerns and only one web dev .. RN is a no brainer.
It kinda occupies a completely different valley of the fast/cheap/good graph