I think altcoin will not control the crypto market, because this bitcoin is the king of all coins, and altcoin is his warrior so it will not be possible the king is defeated by the warrior, without the bitcoin definitely altcoin never existed, and if we invest in altcoin more at risk than invest in altcoin, so bitcoin still leads the market
Altcoins price do only follow on what is the current value of bitcoin. Therfor bitcoin will still the winner if we are going to compare them both. Though alts has a wider range of coins that may seem to be more indemand when comapred to bitcoin because majority of people are into trading .
But overall , it does not really matter whether alts or bitcoin can take control of the market because more important is there are still crypto that we can use in order to earn a profit and to use for useful porpuses