Why Is IL Considered a Risk for LPs but a Benefit for Arbitrageurs?

Impermanent loss is the opportunity cost for the LP, but it creates a profit opportunity for arbitrageurs. When the AMM's price diverges from the external market price, arbitrageurs step in to trade against the pool, bringing the price back into equilibrium.

This trade generates the fees for the LP but also causes the IL. Arbitrageurs profit from the price difference, which is the LP's loss.