Those are the pure hearts, not the purity heart.
"The Pure Hearts are great treasures created by the Ancients. They supposedly hold great power. The source of power in these Pure Hearts are the power of love itself (parent, smitten, etc.). The Ancients researched love, believing it to be the universe's only salvation. They created the Pure Hearts as the embodiment of love. Hopefully, their combined brilliance would negate the destruction of the Chaos Heart, a feat which it ended up successfully performing. Mario and his team of heroes must find all of the Pure Hearts to destroy the Chaos Heart. In the end the hearts defeat Count Bleck, Dimentio and The Void."
^Stopping Multiversal forces > Dante.
Mario already gathered together and assembled the entire purity heart aswell. Even if it takes a moment to use, Mario starts wth a star, and the Purity heart, IIRC, /recreated the multiverse/ sort of putting a dent in the idea it can only interact with the chaos heart.