Any time a hero is required in virtually every team, it's a problem. Bone was a problem, and DS was a problem, and at various times in the present or past, Wolf, KK, DM, Medusa, Hydra, Spider, Kaiju, Bard, Megataur, Skeleton King and more. And when the solution to a problem is to release a new hero specifically designed to counter it, that's almost guaranteed to create a new problem.
DS should not have been released. It was released with a known bug, which is that she was supposed to protect each hero's energy individually, not the whole group's. In other words, if Bone drains 300 energy from each hero, that was supposed to knock 1500 off of DS's banner. Instead, it only knocked off 300. She was supposed to spur an expertise race, not a starting energy race.
But the problem is much deeper than DS. Yes, DS should not have that bug, but Bone shouldn't drain nearly as much energy, and DM shouldn't grant nearly so much energy, and River runes shouldn't multiply DM's energy boost, and Wolf and KK shouldn't cancel whites for so long, and Medusa shouldn't have disabled for so long, and there shouldn't be so much tenacity, and, and, and, and, and.
If balance had been a priority, all of these problems could have been fixed a long time ago, but instead, they just kept releasing counters, and counters to the counters, and counters to those counters. That's why we're in a boring mess now, and that's why the next "fix" will put us in some new boring mess.