Bitcoin is popular because the exchange rate has been increasing a lot (much more than most other assets)
Bitcoin is popular because confirmed transactions are irreversible (unlike most bank transactions)
Bitcoin is popular because participation is permission-less (unlike participation with banking systems)
Bitcoin is popular because transactions do not require trust (unlike bank transactions)
Bitcoin is popular because it is decentralized (unlike banks and your local currency)
Bitcoin is popular because you don't need to give up your privacy (unlike bank accounts)
There are a lot of reasons that bitcoin is popular. Transactions are also typically confirmed in an average of 10 minutes if you pay a high enough transaction fee. You can choose any transaction fee you like, with the knowledge that lower transaction fees simply mean waiting much longer for confirmations. Do you get to choose any fee you want when you pay bank fees?