I don't think that will happen, bitcoin is the reason why altcoin are here without bitcoin there will be no altcoin, the movement of bitcoin will keep affecting altcoin paired to it, that is why some altcoins are only paired to usdt only due to what bitcoin movement do cause
Yes, but there is also Altcoin that is paired on both, and that is also good, namely on Bitcoin and USD, so when Bitcoin is moving, Altcoin will also experience the same thing even though the percentage increase is not the same, meaning that the pair of Bitcoin and USD are equally good when paired with an Altcoin.