Real World Example

In old React 16 projects, reading e.target.value inside a debounce or after await returned null because of pooling. Today pooling is gone, but e.currentTarget still becomes null after the handler returns, so read what you need before the first await.

async function handleSubmit(e) {
  e.preventDefault();
  const data = new FormData(e.currentTarget);   // ✓ read before await
  await checkCaptcha();
  // new FormData(e.currentTarget) here would fail: currentTarget is null now
  await fetch('/api/signup', { method: 'POST', body: data });
}

// React 16 code you may still find in old projects:
function handleChange(e) {
  e.persist();                                  // needed for pooled events
  debouncedSearch(e.target.value);
}