We can see, only some of top altcoin was trying to follow the btc rally during its $30k to $40k journey but except those, no other altcoin is following the rally.even there are some old coin in my wallet, are dying due to lack of investment.because people are selling their altcoin & invest on bitcoin for more and more profit.that's why middle ranked altcoins are dying and they failed to reach the ath when bitcoin pump 2x of its 2017 ath
I know many investors who are suffering from holding old altcoins that have been laying down in the dumps like anything. The best way to get out of them is to sell at whatever value possible and then forget about them. You might be at a loss, but it is better to move on and accept the loss than keep holding them. Bitcoin has shown its resilience over time and this does not need more evidence - altcoins are shit when compared with the price metrics of bitcoin even when reaching maintaining price.
I would suggest you to move away from altcoins other than the top 10 altcoins. Then go with bitcoin for the long term.