I believe, Bitcoin as the oldest and #1 crypto currency has already taken its niche in the digital world.
The main role of altcoins, in my humble opinion, is to create Bitcoin the free market environment and bring more competitiveness. They are used more to earn gains in fluctuations and then convert to Bitcoin again.Frankly speaking, only Ether actually stands out of the hundreds of other tokens . It is backed up by a really disruptive tech and as Bitcoin it is kept decentralized.
Guess, in the mid-term future there will be only 2-3 altcoins rivaling the champion. As for national government regulations, they influence the whole cryptocurrency space world-wide dumping prices and creating issues. Guess, more new regulations and tax rules are to come on stage as many countries now still define their official attitude to the cryptomarket in general.