Toby brings more versatility in combat. You’re right. But if we’re talking meltdown still, team fighting is only a secondary priority. Unlike incursion where a battleborns presence is always necessary in some fashion, preventing that minion wave from entering that grinder at all costs is paramount to victory.
Ernest doesn’t have that kind of versatility, but he doesn’t need it. The point is the minion wave is cleared before it even comes into contact with your own as Ernest can bombard accurately from behind one grinder all the way down past the other one. And pushing Ernest off a spot is a lot harder than it sounds, especially if he’s dropped a few of his explosives around him or his ultimate.
He pushes as good or better than anyone else in the game, spraying high damage splash attacks before him and clearing waves with impunity. He locks down areas with his skills and gives high buffs to his teammates or himself in a large area. On top of that, and the point of this thread, players can now hit sentries from behind walls. That’s not just a map flaw that needs to be addressed. Even if they fix the overgrowth wall, less well known exploits still exists. Ernest can also hit the sentry over the chokepoint ledge on monuments. While his team fights near the ramp he can just fire right over the top of it. He can also bounce his bombs off the center column at the sentry steps in Echelon and they will roll right into the sentry. Those are not so easily fixed.
He’s not an outright broken character, but he has completely unbalanced damage potential. A single character choice, character mind you not player, should not single handedly have the capacity to change the flow of the game despite opposing tactics. And Ernest does.

Glad someone else sees his incredible badassery.