Facebook can make software great because they have great engineers, but they've suffered a major case of scope creep, which leads to more than a few loose ends as the company assigns their best engineers to [choose your own adventure]:

- maximum profits (woohoo!) - reaction to potential regulation - unwanted press attention - wanted press attention - the shiny new thing

That's why I never switched to React. It's a good way to organize things and was clearly well engineered from the start, but there are other choices besides React (and RN) where leaders have demonstrated their willingness to stick with it through thick and thin because...it's all they do.