why to avoid Optional Chaining Operator code example

Example 1: optional chain operator

const adventurer = {
  name: 'Alice',
  cat: {
    name: 'Dinah'
  }
};

const dogName = adventurer.dog?.name;
console.log(dogName);
// expected output: undefined

Example 2: optional-chaining operator

if (user?.team?.subscription?.invoices) {
  //
}