Yes, applying compositional patterns and one-way data flow is most appropriate for all apps, independent of scale. Why? Because developer A (author of app x) leaves company. Developer B gets hired. Developer B is onboarded in an afternoon because things can be understood at a glance thanks to functional patterns and one-way data flow.
Having built many large-scale Backbone apps, anytime someone new came on board it was really very, very difficult, no matter how many design patterns one applied.
React's innovation was making FP mainstream. And then teaching the value of simplicity, as a principle. And yah, if something broke, it might be a little opaque, but at scale and in general, things broke _way less often_.
This is also the reason why most devs are full-stack now. Back in the day backend devs wouldn't dare touch FE code, and now its "not so bad", and pretty much anyone can work all over the stack.
Having built many large-scale Backbone apps, anytime someone new came on board it was really very, very difficult, no matter how many design patterns one applied.
React's innovation was making FP mainstream. And then teaching the value of simplicity, as a principle. And yah, if something broke, it might be a little opaque, but at scale and in general, things broke _way less often_.
This is also the reason why most devs are full-stack now. Back in the day backend devs wouldn't dare touch FE code, and now its "not so bad", and pretty much anyone can work all over the stack.