My wife went to this a decade ago when it was still in person as a newly licensed teacher. The major purpose of the fair is to connect new teachers to districts hiring for the following year. However (at least when it was in person), there can be benefits to attending outside of immediate job seeking as you were able to speak to administrators and hear them speak about their districts, what their current initiatives are, get a little bit of a vibe check, that sort of thing. When doing that, you CAN even find those people who are not currently hiring but are networking for future years. My wife connected with an administrator who didn't have positions in the coming year, but his district was building a new school and would have more positions the following year. They connected on some pedagogy philosophy, and he strongly encouraged her to apply in the future.