Yes, dugtrio has more uses than just checking Heatran, Ninetales, and Tyranitar. It's a good check to both Volcarona and Terrakion, and, if you're playing against a team where some of these threats are already gone or simply not present, it can be used as a last ditch effort to cripple an opponent's sweeper with Memento. As the above poster said, Gothitelle works really well for trapping several walls. Wobbuffet isn't that common because it has a hard time coming in on anything but walls, and doesn't even deal with them as well as Gothitelle. It does have the advantage of having encore, so it does still have a niche. Trappers can't trap baton passers btw.