In that case, that coin would really have a good potential. I cannot see any new coin that can replace bitcoin yet. As we all know, a lot of people already trusted bitcoin and they consider it as the main currency because it's the first cryptocurrency to become very successful and bring convenience to everyone.
This is true. But just like in economy there is competition. One may rise and the other may go down. But it is better for the market if the bitcoin stays at number amd stay being the king of all coins because it is the reason why more people uses cryptocurrency . But if it happens, then so be it. People is good at accepting changes.