When talking about the future of the Bitcoin and Altcoin. I would argue that there will be Altcoin which could pass through the achievement of the Bitcoin. But this definitely takes a very long time. New Altcoin nowadays many appearing and of all that there are certainly some coin scam. And you have to be careful before investing.
Oh yes...Too many years should pass before it can happen or IF it can happen. Bitcoin is so popular that it will be extremely difficult for any cryptocurrency to become better than BTC and get the same popularity.