Help me understand why I care about effective APR in a scenario where it has no impact on the amount I am charged? The customer for this product is agreeing to

Help me understand why I care about effective APR in a scenario where it has no impact on the amount I am charged? The customer for this product is agreeing to a fixed amount of interest in the form of a “fee” and nothing increases that fee. A customer who wants $25,000 for less will get a line of credit, but will then risk their assets as collateral.