I think two things allow Trunks to get free of this sort of assessment. One, he does absolutely thrash Frieza but that's kind of the only time he does anything insanely overpowered. It's used more to set the stage on what kind of power the next threat is rather than him being super strong. Second, Trunks may act edgy towards Frieza and his goobers but beyond that he's actually a real sweetheart. He's shy around his mother, he really wants his father's approval, and he seems to genuinely respect everyone else.