Nothing alts have chances against bitcoin because bitcoin is the main cryptocurrency that buy anything alts. And they used bitcoin everytime they want to buy altcoin or they exchanged altcoin to bitcoin so nothing reasons.
I think it is too excessive when altcoin has the possibility to shift the bitcoin from cryptocurrency number 1? Because I think bitcoin is too superior. And will be very difficult to replace
It is difficult yet, possible. Bitcoin and altcoins are very different but they are the same in usage because they are all online currency. Altcoins has a lot of different features that can be used against bitcoin so if the features of altcoins are better than bitcoin then there will be possibility for bitcoin to be replaced and that time will come soon.