Bitcoin fees are already much lower than bank transfer fees when you send money overseas. And when bitcoin forks to solve this transaction fee problem then it'll be nearly free. It's really not a good argument to say that because bitcoin has a fee and another altcoin doesn't, bitcoin isn't going to have a future. In fact if near instant confirmations and no fees on transfers is what you're after, as well as low volitility compared to bitcoin, then there is already an altcoin available called Steem Dollars. You can send/receive with 0 fees no matter how many times you do it and steem dollars are somewhat pegged to the value of a dollar.
Bitcoin is a bit like gold, in the sense that it's a good store of value but probably not designed for instant day to day transactions. Sure, there might be some altcoins that will exist alongside bitcoin and be successful(ethereum etc.) but bitcoin will be #1.
Yes perhaps Bitcoin will only be regarded as a store of value, digital gold type of crypto in the future, ceding the everyday currency role to another coin. Which I think is fine. I could still see a several trillion dollar market cap on Bitcoin eventually even with it just being an investment vehicle and a safe haven asset. Afterall, I agree with a previous poster who said having a limit on coin supply doesn't allow usage as an everyday currency. Precisely because a supply limit means disinflationary which means bitcoin should be expected to increase in value until it has full globalization as a investment vehicle and safe haven asset (could be worth hundreds of thousands of dollars by then), which means it is always much smarter to buy and hold bitcoin rather than spending it.
So perhaps a crypto with a constant rate of inflation that matches what we expect of fiat - say 3% - would be better for use as an actual currency. Though of course the problem with using any crypto is that the only way it will be adopted in the first place is as an investment vehicle. That's the entry point use case for cryptos. People will only be interested in it if they can make money on it. Once a coin gains wide global adoption then to become a relevant currency it needs to have stability, which means its annual inflation would need to be set yearly to match the inflation of fiat currencies (perhaps going off of the dominant fiat currency - USD right now).
This would allow it to be used as an everyday currency, but not as an investment vehicle. The tricky part is the transition between these two though. Would the people who bought it as an investment move their money out once it made the transition from growth to stability? It's fundamentals as an everyday currency (near-instant transactions and very low fees) would have to be rock solid and people would have to start using it as a currency in large numbers before the developers enacted a fiat matching inflation rate to make it stable because then investment people would probably move their money to other investments.