Some cards utilize Toss as a powerful winning strategy, such as Foreign Spearman and Roman Spearman. These attempt to play enhancements with high strength to outright kill opponents by decrease.
Other cards, such as Coliseum, TSA, and Mighty Warrior use Toss as a deterrent. Coliseum and TSA toss CBN enhancements - you might run Coliseum in a fight-by-the-numbers banding deck so that your main counters (cards like Scattered and Abandonment) don't work. You use TSA similarly - Angel Party decks tend to band in lots of angels and cap it off with Captain of the Host, so stopping the big AoEs is important.