Given that Bitcoin is considered a store of value, can you use a cryptocurrency that can guarantee day-to-day usability? How to go to bakeries, fill up the car, travel, etc? Do you know any coins like this?
If you think you will find a coin that will be more accepted than bitcoin, forget it. Bitcoin with lighting is very perfectly usable as a daily currency, so there is no room for an altcoin.
A bitcoin transaction is slower compared to some altcoins, some altcoins send a transaction in half a second, Bitcoin can't do all this alone that's why it won't be the only coin that survives in the long run, any smart merchants out there must be willing to accept more than just BTC as means of payment.