Looks clean, but hides serious issues:

Performance Pitfalls
-  [...] creates unnecessary arrays & memory bloat.
- const copy = [...arr] doubles memory for large arrays.
- Nested spreads ([...foo, ...[...bar, ...baz]]) slow things down.

Better Alternatives
- arr1.concat(arr2, arr3) – avoids extra memory.
- arr1.push(...arr2) – modifies in place.

Use ... wisely! Cool syntax ≠ best practice.
Have you hit performance issues with spread? Let’s discuss!