Why Is the Forfeiture of Time Value Less of a Concern for an American Put Option than a Call Option?

The forfeiture of time value is less of a concern for an American put because the proceeds from early exercise can be immediately invested to earn interest. This interest income can offset the loss of time value, making early exercise more often rational for a deep in-the-money put.

For a call, the holder would have to borrow money to buy the asset, which is a cost, not an income.