It can be replaced but only after someone convinces enough of its participants to abandon the network for something else. Thats not likely anytime soon. Not as a monetary/savings asset anyway. A fork is actually more possible in the near future. But even that is not likely to happen.
So, as it stands, BTC is king. There are other “coins” that are fundamentally similar. Or even better. But sometimes it’s better to already have widespread usage and adoption than be released later with improvements.
You fundamentally misunderstand what Bitcoin is.
You say "a fork is actually more possible in the the near future".
ANYONE can fork Bitcoin. It's not even hard. What you meant to say is that it is more possible that a fork of bitcoin might achieve some level of acceptance by the rest of society.
Bitcoin is nothing more than a collection of computer programs that communicate over a mutually agreed protocol. Any individual, or group of individuals that change the accepted protocol have created a fork.
Just apples and oranges with maxis on here.
Bitcoin is fantastic at being Bitcoin. It sucks at being Ethereum, or most any other utilitarian token.
I'm not dissing Bitcoin, but to limit blockchain technology to purely monetary transfers is insulting to the potential of the technology.