Bitcoin can't, but faster cryptos would be able to. The main issue we have are the tx fees and the blocktime.
I totally agree! Hopefully BTC can adjust to be quicker in the future.
For me bitcoin can not replace fiat because bitcoin is not yet legal so how it will happend that bitcoin can replace fiat, And bitcoin now is getting more popular but until now it is not yet legal, so i think even it became legal in years to come it will not be able replace fiat but to do what the fiat can do is very possible in the future.
Yes the future of the bitcoin is good and a lot of the people are trying to invest in the bitcoin and this is the reason why a lot of the people are using the online shopping and the best part of the bitcoin is the huge use and the online payment I hope in the future we will see the bitcoin will become the only currency and this Is the reason why a lot of the people are buying the bitcoin and the value of the bitcoin will be very high and it is the reason the bitcoin is very famous.