I think in short term every thing is possible as we experienced high increase in prices of most of major altcoins such as Ethereum. But in long term everything depends on what will happen to Bitcoin.
In my opinion in future we will have only one acceptable cryptocurrency. If Bitcoin can solve its problems like high transaction fees that you mentioned, It will be that cryptocurrency. If not we should wait for another cryptocurrecncy that will replace Bitcoin.
We should also consider another important issue which is governments decisions. In future after accepting bitcoins by entire world, Governments would like to have more control on the system. We should wait for their decision whether they want bitcoin to be that major cryptocurrency or not.