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

I strongly believe in bitcoin and also think the 0.1BTC even as at today's price isn't really much for a house let alone a mansion in my location and I don't think it also has to take 50 years for bitcoin to be accepted all over the world and this might never happen anyways. That said, see where bitcoin is in less than 2 decades of its existence, impressive, so this means people have now had better ideas to develop what could be better, not impossible. At the end of the day, guess time will tell.