Bitcoin has real use and true value, so it can't possibly die due to a market crash or anything like that simply because this use value is real and it is not going to disappear overnight just because prices went down a few dozen percent. On the contrary, lower prices will only expand its application. While bitcoin had been rising in the past, its use value passed on to some altcoins, for example, litecoin. Now we see things develop in the opposite direction. Bitcoin's use will expand while the use of altcoins will constrict. That likely explains why we see altcoins falling faster than bitcoin. Bitcoin is just claiming back what it had lost due to its rise in 2016-2017.