Isn't that one of the main points of React and its ilk? The state is just a big JSON object, and sometimes you might be fetching a bunch of data that makes up that state, and streaming it in. If latency is high and volume of data is high, seems perfectly reasonable to get the UI rendering as the state comes in instead of waiting for the last byte to do anything.

For instance, imagine you don't fully control the backend to split up a large response into several smaller API calls, but you could render the top part of the UI, which may be the most useful part, from the first couple of keys in the JSON, while a large "transaction history" after that is still downloading.

If your UI layer can't efficiently update when you get new characters, you've got bigger problems than JSON parsing.

Seriously, you should be able to update the UI with a new character, and much more, at 60fps easily.

hmm this makes sense for LLM usage

(but for other uses - nope)