Very few people are unique, so what's the point in mentioning that in a tiny sentence if you're not going further with it? Perhaps the insight comes... one reply later?
Very few people in any industry have a truly unique set of skills. And in jobs that can be easily remoted away like software, that quantity is even less.
Unique in this context doesn’t mean absolute uniqueness, it means your skills aren’t widely available.
The world needs experienced Go developers for an example. Being able to hire one remotely may increase the available pool of Go developers you can hire, but it doesn’t make them cheaper. That’s because hiring remotely also increases the number of employers chasing the same few Go devs.