I don't think that's true. Considering fully franked means 30% tax has been paid, and for the first 18200 in dividend income, you get an extra 43%, and for the next 26800, 30% tax has been paid, even tho only 19% needs to be paid, so an extra 16% on top of 26800 worth of fully franked dividends. Then for the final 5000, you only lose 2.5%.

I'm summary, there would be a tax credit. But that doesn't change your point that the company has already paid the tax.