const users = [
  { name: 'Ada',  score: 91 },
  { name: 'Linus', score: 78 },
  { name: 'Grace', score: 96 },
];

// Copy, not mutate — `users` is untouched
const ranked = users.toSorted((a, b) => b.score - a.score);

const top = ranked.at(0);              // no ranked[ranked.length - 1] dance
const last = ranked.at(-1);

// Group without a reduce()
const byBand = Object.groupBy(users, (u) => (u.score >= 90 ? 'high' : 'rest'));

// Replace one index, immutably
const patched = users.with(1, { ...users[1], score: 80 });