Bitcoin and altcoins has different uses and its base on their supporters if they think the specific coin is worth to buy and hold. Majority of altcoins cant even reach half the price of their last ath but its not a problem since we can choose where we want to invest our money to the coins we believe in.
Bitcoin is undeniably the most reliable coin for investment. It can turns up and down but will surely recover even it takes time. Better to not look on the price. If you truly believe in btc even the price is in dip you'll buy because you're confident for its future.
Most alts can't recover as they have no use case in the first place. Most alts were created to fund the pockets of the devs. So once they hit the exchanges, the price is in continuous decline, with no sign of recovery. Only those with real applications and continuous development will survive and that is small in number. Whereas, btc, will go up and down in the market but this one will always be the number 1. And seems that we will 20k very soon.
Altcoins are easy to create and indeed they are only chasing money to fund their half-way plans, so now I don't really think about alts flying because at the end it will go to the bottom too, see many maybe hundreds of altcoins that are made but break up in the middle of the road that means The developer does not think about the future but after reaching the exchange maybe their main goal and the products offered are not very popular, so altcoins will not follow bitcoin even though it is currently on the rise.
It's too big to hold alts at risk so I decided not to be long and it's better when the trend just occurs.