Bitcoin - lower fees, you have your own bank, transactions is easier and faster, identity of the owner is anonymous, volatile value
Fiat - higher fees, you need some company to put your money on, transactions takes some time and requires some verification if you are owning a large amount, stable value
Yes and in fiat you cannot huge amount of money with you physically as there is always a chance of money getting stolen or getting robbed but with bitcoins you can carry any amount in your bitcoin wallet and no one would be aware about it.
And no one needs to explain why this money is in my account. And no one can ever freeze my bitcoins in my wallet.