I am grateful to developers making sites lightweight that load on my 2G connection in a village in Serbia with a 150MB monthly data cap. I'd like to use Opera Mini more but it breaks many websites so I use Firefox and hope for the best.

Then maybe "if you serve to mobile phones in third world countries" don't use React?

Facebook serves to mobile phones in third world countries.

In what way does this invalidate what I wrote, which, if I have to make it even plainer, is:

If you're serving to mobile phones in third world countries [and you're concerned with React's size], then you can always NOT use React.

Apparently Facebook is not concerned with that, or doesn't consider it a problem for third world networks.

But for those people that complain about React's size and third world usage, they do know that there are tons of lighterweight options, right?