JSFiddle - React, Tailwind, and code Playground

JavaScript

const state = {
  1: 1,
  2: 2,
  3: '23',
  4: {}
};

const deleteKey = (k, obj) => Object.entries(obj).reduce(
  (newObj, [key, value]) => {
    if (key != k) {
      newObj[key] = value;
    }
    return newObj
  }, {}
);

const deleteKey2 = (k, obj) => {
  const newObj = { ...obj
  };
  delete newObj[k];
  return newObj;
}

console.log(deleteKey(3, state));
console.log(deleteKey2(3, state));