Cash is not as easy as you say. You can't just have $50 cash and pay for something that costs $50. You have to pay sales tax, too. So, if you want buy something with $50, it has to cost $46.19 so that you can add the $3.81 in sales tax to make it an even $50 (CA sales tax is very high). Or, you can buy something for $50 if have another $4.13 with you.

You think that is simpler than a 0.01 BTC transaction fee?

BTW, your "Bitcoin requires to have 100+ IQ" comment is funny because a 100 IQ is average. Only half the people in the world have a 100+ IQ, but the comment still made made me chuckle.