if you're a startup or small shop.
if you have to deal with any native code that expects to know something about the dom, now you just forced that code to do expensive and constant polling algos because you completely pulled the dom from under its feet.
Like Facebook? Netflix? The BBC?
facebook = probably hack away all the low level stuff they need to tweak.
bbc = they probably have the same problem we have here. that does not stop them or we to boast that we use react all over the place. doesn't mean we like it.
with react, they will get inconclusive results because their code might run while they are virtualized or god forbid during the render. and you will only get garbage ads because now they consider you a garbage publisher.