Does it make sense to believe that Bitcoin could one day be replaced by another cryptocurrency, that is, a cryptocurrency that really does make Bitcoin obsolete?
No this won't happen because bitcoin is already famous world wide and millions of people is using this coin. If it has to be replaced by other coin then only way is there That is to launch another coin and wait till that coin gets famous like bitcoin.
I think so. The bitcoin is the most popular digital coin now. If there is no big bug in the development, it will stiil be the number one coin.