bitcoin is way too much popular, every newbie steps into crypto world with only bitcoin knowledge. if any alt coin wants to surpass bitcoin, it needs to have some record breaking moves which can make it to the news and spread the word.
One possibilities I can see on how bitcoin can be surpassed by an altcoin is still the major advantage of bitcoin which is the huge demand and huge market adoption. How could it possible? With the big gap of bitcoin to altcoins, one good altcoin should be backed by a large community, a government, and social media. Through this, the legalization and implementation of a universal digital currency that will unite the whole world might surpass bitcoin as it will attack bitcoin on its weakness. It is the bitcoin's volatility.
In order to make this happen, that crypto should be a stable coin.