This was an annoying lesson to learn.

An empty string is not nullish it is falsy.
Nullish is not the same as falsy.

const x = '';

const a = x ? x : 'abc'; // a = 'abc'
const b = x ?? 'abc'; // b = '', b != 'abc'

In the above example I expected constant B to be ‘abc’ but since an empty string is not nullish and ?? checks for nullish values it is not.