The very big problem that bitcoin solves is the problem of intermediaries and third party problems, we are free to make transactions wherever we want, and we are free to keep our assets for as long as we want, because bitcoin is not controlled by anyone, only we ourselves are in control of the bitcoins that we have, the difference between bitcoin and government currency is that the supply is limited, bitcoin only has a supply of 21 million, while the state currency continues to be issued by the government without any limits.
The other difference is that even though bitcoin could be tracked, you could maybe never know which person an address belongs to. Some addresses could be found, but there are still so many wallet address' that we do not know who it belongs to, which means that it would not be possible for anyone to know what we are spending our money on. That type of privacy is also a big thing, in regular life fiat is tracked very carefully, hell even the money we own have numbers on it, so it can be tracked however we want to.
This is why bitcoin is far better, it is truly decentralized and that gives us a good power and that means it is going to work out in the end for bitcoin and beat fiat clearly.