One big thing I can think of is that every time you use a credit/debit card, a transaction fee goes to a big bank/payment processor.  With btc, it goes to a miner.

Other than that, how does it benefit you to use btc?  I mean you need fiat to get btc, and then usually need to take fiat out.  So where is the net benefit besides the fees being lost by the big banks/payment companies?