Depends. If no one else is doing that particular thing, then by definition you're the world expert. It doesn't matter if there are other people who could hypothetically do it better; they're not in the game.
I have a current hobby that most able-bodied technically minded people could do better than me (genetic joint condition), but as far as I can tell I'm accomplishing things no one else has.
Doing it as a hobby just means that you don't do it for money, not that you aren't good at it. For example often your hobbies overlap with your work. I program games as a hobby and program/design extremely performance sensitive things at my job, they overlap quite a lot.
If you love doing something (which is the origin of the word "amateur"), you're likely to be good at it. If you're a professional, it just means you get paid.
Amateurs care primarily about the pursuit itself, while professionals care primarily about their paychecks.
Hobbies I hate. By definition I'm an amateur and I don't perform well. At my job, I get to exercise the skills I'm best at.
I can't do any old job though. I have to be able to trace at least a thin line from what I'm doing to the broader society.
I know this isn't a common opinion, but I encourage you to at least consider that work—while not fun—is at least a fulfilling way to spend your time. This should be the case regardless of what you do or how much you make.