Yeah you can create another altcoin that is better than bitcoin. But better based on what factor? There are altcoins out there that has better confirmation time. Again, there are coins out there that have scalable block size causing faster confirmation time and speed.
There might one day be a such altcoin that might become better than bitcoin in such a way that it will be used for daily transaction as a regular currency. But this does not mean that it will replace bitcoin. People will still use bitcoin as a store of value.