Belief is not a choice, you’re either convinced or you’re not.
Wikipedia can also be wrong on various topics so let’s not get nitpicky. But, if you want to look up Gnosticism on Wikipedia, you’ll see that being a gnostic means having knowledge.
So people can be either theists or atheists and at the same time gnostic or agnostic.
A gnostic theist would mean they believe and also know a god exists.
An angostic atheist doesn’t believe and also doesn’t know a god doesn’t exists. That’s most of us atheists.
So people can’t be on the fence and say I’m agnostic, that doesn’t tell anything about what they believe.
And when it comes to belief, you are either convinced or you’re not. There’s no middle ground.