JSFiddle - React, Tailwind, and code Playground
JavaScript
const x = [{id: 1}, {id: 2}];
const y = [{id: 2}, {id: 3}];
const ids = new Set(x.map((i) => i.id));
console.log([...x, ...y.filter((item) => !ids.has(item.id))])
console.log([...new Set(x.concat(y))]);