In Miraculous Ladybug, the Ladybug and Cat Miraculouses are supposed to be the strongest. We know this from the fact that, when combined, they give ultimate power, and from their fact that their kwami are the oldest and most fundamental (creation and destruction). This may even have been explicitly stated. By contrast, the Butterfly Miraculous seems to be in the same "tier" in the box as more modest powers such as the Turtle, Bee, and Fox.
However, the Butterfly Miraculous seems notably more powerful. Hawk Moth probably can't choose the powers of his minions, and he has little guarantee that they'll listen to him, but a typical akumatized villain has abilities much stronger than Cataclysm or Lucky Charm, often covering s broad area, which further usually can be used more than once, giving Ladybug and Cat Noir a hard time two-on-one, and the akumatization also seems to have little time limit (let's not even talk about what happens if the akuma isn't purified!).
Why is the Butterfly Miraculous seemingly so strong?