I am not an AD, so I do not know all the ins and outs of Arbiter, so take this with a grain of salt, but... There are a number of uses for Arbiter.
In a nutshell, it's the official partner of the OHSAA when it comes to assigning and paying referees, registering student-athletes, as well as scheduling for some sports. For instance, I believe that for football, all games must be registered on Arbiter for them to count toward Harbin points for the postseason. But honestly, you are still better off going to individual school websites to get full schedules.
I keep track of boys basketball schedules for 80+ schools for my websites, and for the 2019-20 season, Arbiter was the less accurate/complete schedule for 51 of 81 schools. So in my opinion, it kinds of defeats the purpose (other than a method to assign and pay referees and track student-athletes). The biggest problem is that, other than requiring football games for postseason eligibility, there is no accountability, that I am aware of, to keep the schedules complete and accurate.
I have been entering schedules for a LOT of schools for over 10 years, and I see the same 5-6 applications that schools have chosen to use (and often pay money for) to manage their schedules. There is not one single system that everyone uses. Arbiter could have been that one, but it's hard to inform hundreds of schools that the money they spent on these other systems is now lost because they have to use Arbiter. So schools drop their other scheduling systems to use Arbiter, and nowadays, many school websites just link to their Arbiter schedules, even though those schedules are still not complete or accurate. And the fact that Arbiter cannot display final scores or league standings makes it very limited to administrator-only use and not very useful for fans. Just my opinion.