Bitcoin is very easy to access by anyone, anywhere and anytime as long as there is internet. Maybe that's one very powerful reason, why bitcoin should be used by everyone. And bitcoin will be the future of money for the world.
But what about that people who haven't got asset to internet? Firstly you can thing that all around the world have internet access, but it isn't right...
How can you use it as money and, for example, buy milk in market if fees for $ 1 transaction will be too high?
for now, maybe bitcoin can not apply to those who do not have internet. But maybe one day, there will be a new project that applies bitcoin can be used without the internet.
there are some coins have low transaction costs. maybe that would be one of the uses of altcoin. and there are currently enough projects implemented for the development of bitcoin through altcoin.