Apart from pumping and dumping in altcoins there are just very few of them who could reach some significant price. Otherwise none seems to be reaching any closer to BTC.
Most altcoins wait for Bitcoin price to pump before pumping along, some altcoins also pump on their own due to certain conditions and news which has nothing to do with Bitcoin pumping. Its quite okay to say some altcoins are hardly going to drop to zero market value, altcoins like ETH, LTC and BNB since they have more value and eligibility of reaching significant price.
Reason why not altcoins are safe to invest into, most of them get rugged at the start or between when investors begins to troop in. Bitcoin tops the charts when looking for coins to invest into, all others are secondary investment to Bitcoin after building a well planned Bitcoin portfolio.