BTC is not only the first coin but it has symbolic value for the entire crypto market, one symbol of the blockchain revolution.
Just like gold, there are thousands of metals produced such as steel, aluminum, silver, etc., which are widely used in daily life. but gold has always been the most valuable metal, still number 1.
So there will be no altcoins that can replace BTC although ETH, Sol, Tron or Xrp... have utilities, applications and technologies that are far superior to BTC.
Lol who said that Bitcoin is Irreplaceable ? well Maybe as of our time now indeed Bitcoin is still nothing to be replaced but we also Knew that future cannot be tell in this short time, there might be some changes in the coming years , as the increasing demand and popularity of altcoins are being seen now
Im not sure how long it will take but one thing i know, altcoin will have their time in the future.