In my perspective, I believe that there is no permanent in this world but change, so I also think that in the future, Bitcoin will be replaced by more advanced, more popular and more user friendly altcoin. I think it does not need to be decentralized since masses are already use in using centralized services.
With regard to investment, I also agree that new projects offer higher returns in time-to-profit ratio, but with a higher risk. We have seen many investors burned by new projects so I suggest taking full caution in investing on one...
@ the topic, it may take time for altcoin to overtake Bitcoin but no matter how long it takes, I believe one day a cryptocurrency will emerge that will outperform Bitcoin but before that, let us enjoy the opportunities Bitcoin offers.
The one thing we can say for sure is that it probably won't happen during our life-times..

No one actually knows when it comes to this aspect yet it could neither happen or not on which we know that there's always that possiblity and it will always be basing up with community support and recognition. It is really just that hard to believe that the origin of crypto could be replaced by something or talks about alternative coins/tokens but actually this is something not a sure thing or might time comes that it could really happen yet getting outdated is inevitable but since community support is strong and have that recognition and adoption then it's safe to say that we might not seeing this to happen but of course there's no guarantee with this aspect. The key on here is that you should really that just invest into the amount that you can afford to lose so that whatever happens into crypto space then you won't be finding yourself at great trouble.