0.1 BTC isn't going to be enough because there's competition. In the future bitcoin could be overtaken by rivals so it's possible it'll become worthless.
Bitcoin has not reached its peak and potential and therefore it's not right to think that it may be replaced by something better. Even if this was to happen, it may another 50 years to first completely accept bitcoin all over the world, then to find something which can act as an even better mode of currency. Brother we may not be living by that time
