What benefit do you see with fiat currency? If you can answer this then there's no difference with the bitcoin currency as both are currency used as a means of payment. With bitcoin though you get some advantage since the currency is digitalize and decentralized meaning you can get paid for borderless jobs and stay anonymous unlike with the fiats that all your private information are needed for a job that'll probably just pay you changes.

The opportunity that bitcoin offers, other digitalized fiats or physical fiats do the same. Bitcoin can be used for investment so is the US dollars. For example, the US dollars could be hoard considering if your country's economy isn't doing so great and in years to come you'll get more local fiats if you convert back your US dollars into your local currency.