You mean people still use regionally locked monies?

I mainly use cryptocurrency to gamble or trade, I can make alot of money this way. As soon as I reach a certain amount I sell my crypto and buy fiat as it is more useful to me, it is easier to spend. I only use crypto for certain services.

Bitcoin advantages;

~ Decentralization aspect.
~ Storing money outside the banking system.
~ Sending and receiving money instantly around the world where the amount doesn't matter.
~ Great currency for online payments.
~ Blockchain that can be used for various purposes.
~ Fixed coin cap.
~ Amount of coins pumped in the economy halves every 4 years.

Fiat advangates;

~ Acceptance everywhere in the world.
~ Best payment tool in the offline market.

But there are more fiat gambler then the cryptocurrency gambler as there are more number of casinos all around the world and more gambler too !
yeah but is soon future i think more physical stores will be accepting bitcoin so it will be more important then fiat !

You must need both of them , you work and get paid with cryptocoin and then exchange to flat for your needs.
And the good point with cryptocoins you can earn interest with it and you can send your bitcoin anywhere you want with less fee.

The benefit from using fiat
- You can buy anything for easily in every place in your are or region
-The store is always accepted fiat payment
-It's legal currency with the government regulate

the benefits of using bitcoin
-it's decentralized
-anonymity it's enough for covering your personal data
-easy for using for the online digital transaction

Between the benefits of bitcoin, you can get there are disadvantages for every type currency.

We have very much alike. I do the exact same, but I can't to sell my Bitcoin and get Fiat. But I use BTC to buy Steam keys and digital technologies using a Bitcoin debit card. However, I do think that fiat would be more useful to me compared to cryptocurrency. 

For now, Fiat is the more used by people. But I believe as the time goes by people will start using Cryptocurrency, because it's the most suitable for now and for the future. Because using Cryptocurrency is more practical than using fiat money, you don't have to bring a lot of them in your wallet. So you don't have to worry for your money will be stolen. Well, it depends on how you keep your cryptocurrency. If you do it with the proper way, then you are safe. But if you do not use the best security system to protect your wallet, then you are not that good.

each of them are made for a different purpose, you can't really compare them in my opinion.

fiat has been around for a very long time and it is being accepted everywhere in the world without an exception and all fiat currencies can be exchanged to each other.

bitcoin offers a lot of benefits like the security and decentralization and many other things that others have explained above me. but the problem with bitcoin is adoption.

all other crypto currencies which are altcoins are a lesser version of bitcoin. they have many good features but not all of them are good but some have good future ahead themselves even if today they are sharing a small part of the market.

Prefer cryptocurruncy because they are fast,secure and you have full contol on your money. But it will take lot of time before cryptocurruncy replace fiat or it may never happen in my lifetime