It's not overused because a team is allowed only one challenge. As far as LL umpires (I used to do that level earlier in my career), the current ones at this World Series and the preceding regionals are not that impressive, an alleged "10 years training" notwithstanding. In MLB replay cannot be a disadvantage because it's accessible to all teams at the same time and in the same manner. It's used in a very limited capacity, when an umpire's eyes and ears cannot humanly tell if a ball hit a railing, went out in flight, etc. In LL Baseball, it's not used universally and consistently. It also teaches the kids a poor lesson in baseball and life.