For循环内部的filter方法不能按预期工作

const arr = [1, 2, 3, 4, 5];

const result = [];
for (let i = 0; i < arr.length; i++) {
  result.push(...arr.filter(item => item > 2));
}
console.log(result); // [3, 4, 5, 3, 4, 5, 3, 4, 5]

const arr = [1, 2, 3, 4, 5];

async function processArray() {
  const result = [];
  for (let i = 0; i < arr.length; i++) {
    await new Promise(resolve => setTimeout(resolve, 100));
    result.push(...arr.filter(item => item > 2));
  }
  console.log(result); // [3, 4, 5, 3, 4, 5, 3, 4, 5]
}

processArray();

const arr = [1, 2, 3, 4, 5];

function processArray() {
  return Promise.all(arr.map(async item => {
    await new Promise(resolve => setTimeout(resolve, 100));
    return item > 2 ? item : null;
  })).then(result => result.filter(item => item !== null));
}

processArray().then(result => console.log(result)); // [3, 4, 5]