given that the amount you are suggesting guarantee the transaction, in my opinion it doesn't,
You are welcome to your own opinion.
I'll stick with the facts.
$3.90 to transfer the equivalent of $20 worth of bitcoin is around 20% premium on the transaction. A credit card charges 3% to the merchant.
The fees system was designed by Satoshi to INTENTIONALLY DISCOURAGE use of bitcoin blockchain transactions for smaller value amounts. This makes sure that there is always space available in the blockchain for the transactions with the highest value to byte-size ratio.