maybe there will be a replacement for bitcoin in the future. because we can't predict anything too far in cryptocurency. because something we didn't expect will happen in crypto. but for now there is no altcoin that can compete with bitcoin with its various advantages. many reasons bitcoin is better than other altcoins today.
Possibly, anything can still happen in cryptocurrencies in the future, but by looking at Altcoins which always depend on Bitcoin price movements, it may be very difficult to replace Bitcoin by Altcoins.