Is bitcoin will end up being the sole currency the world will ever need in 10 years’ time?
I don't believe that Bitcoin will the only crypto that the world will ever need because while Bitcoin gets older it's network become slower and it's not the ideal crypto that people will use on their everyday life because there are so much altcoins can offer more than Bitcoin's.
Ripple, DogeCoin, UCash and other Billion coin supply altcoins are offering fast transaction speed that the transferring of coins between wallets will be successful in just as fast as a couple of seconds.