The photographer wants you to believe that they’re the only photographer for you.
Often a photographer trying to gain your business will in some way try to convince you that they’re the only photographer available to help meet your specific needs.
Sometimes this may actually be true, depending on where you live and other factors. But in many cases, it’s really just a marketing tactic in order to convince you to commit.
Generally speaking, there have never been more photographers available to meet your needs in the history of photography, than there are now.
Some photographers are better suited to meet your needs than others — so make sure you can see yourself in their work and you are confident from their presentation — or better your interaction with the photographer — that they are the right photographer for you.