JavaScript speed comparison: [...array] vs. array.concat()

a.js

const a = Array.from(Array(1000_000)).map((_, i) => i);
const b = Array.from(Array(1000_000)).map((_, i) => i);

const times = 1000;

console.time("spread");
for (let i = 0; i < times; i++) {
    const c = [...a, ...b];
    c.length;
}
console.timeEnd("spread");

console.time("concat");
for (let i = 0; i < times; i++) {
    const d = a.concat(b);
    d.length;
}
console.timeEnd("concat");

Node v17.8.0

node a.js
spread: 11.645s
concat: 4.486s