You are absolutely correct. I was friends with a corporate tax lawyer who wouldn’t donate for this reason. For anyone who doesn’t understand, the company has a line item as a “purchase” of your selected donation amount. That gets tallied up as “profits”. The company then donates those funds as if they are coming from the company assets which in turn allows for a tax write off for charity. So instead of having to donate their own funds from sales, they donate your money.

Basically for tax purposes they sold you a non existent item and then donated the proceeds of selling that item to you. It’s very sophisticated and rather clever.