My opinion is that in time Bitcoin market share will keep reducing, as many other coins and tokens and platforms will keep surging.
In the long term, the blockchain technology is very disruptive. Bitcoin will more likely compete with Gold, Ethereum will provide a backbone for many uses.
So I am not really sure a collapse is incoming, it depends if a real bubble will quickly form.
Bitcoin market will not collapse because cryptocurrency will just continue to grow, the volatility of the market will make the price of bitcoins to grow even more due to the demand in the market that keeps on decreasing whenever a dumping time like today occurs.
Increasing of numbers of cryptocurrency is just fine because not every coin in the market does have the capability of increasing its own price if people will not choose to invest on their coin.