Simulate global state tradeoffs in React concurrent mode

If you aren't sure why state tearing was a hot topic a few years ago, when React's concurrent mode was first discussed, this github discussion should help: https://github.com/reactwg/react-18/discussions/69.

Tanner Linsley had a great post on twitter that suggested that concurrent rendering was fundamentally at odds with fine-grained reactivity, so to better understand what he was talking about I decided to write this demo.