I think it is not true. Bitcoin will be no.1 cryptocurrency forever. There is no altcoins that can beat bitcoin, People will still continue to patronize bitcoin. Bitcoin will become international currency in the near future.
If you notice then there is a coin that continues to increase marketcap, the coin is ethereum, a year ago marketcap ethereum no more than 15% of bitcoin, but today marketcap has reached more than 60%, and if the increase of ethereum continues to happen then within 2 years will be defeat ethereum.