SOURCE

const arr1 = ['', '100', '120', '125', '125', '130', '130'];
const arr2 = ['', {id:'120'}, '125', '125', '130'];
const arr2_copy=[...arr2]
const arr3 = [];
arr1.forEach((a)=>{
    let c = arr2_copy.findIndex(b =>a === b);
    if (c > -1) delete arr2_copy[c];
    else arr3.push(a);
});
console.log(arr3)  //['100', '130']