When a boss is ridiculously strong, the devs of a game nerf them. A game is meant to be fun, not to make you enraged. An example: The Elden Rings Devs, they nerfed Melania because she was too hard.
As for the comment itself, i can't really disagree with it, the most boring time i've had in this game is with boss fights, they extend their welcome way too much and after doing it once i don't wanna do another one ever again, except i will do them again because the drops it gives are pretty invaluable, so i am forced to do something that's not fun, unlike Dungeon, which at least is a spectacle seeing your digimon beat endless waves of enemies.
To add to this, with challenges such as bosses there should be a line between something that's hard because it requires you to learn and plan how to beat challenges or use different methods to see what works and something that's hard because it's based on luck.
Also item drops really should be changed to be based on the damage dealt or crits and not a chanced based on rng with any amount of damage, it adds needless grind while making it feel boring to raise a Digimon, which you can see would be a problem.
In fact I'd say the game in general has many balancing issues which expect you to dedicate hours just to even evolve your first Digimon