Its natural that altcoin industry will dump after end of bull run cause after a certain time whales sell their shares and people also started panic sell. And thus actions makes the market downfall or crash. That's why you saw those altcoins were down as if they were dead. But as we are guessing another bull run is on the way, so look at these altcoins once again. They are alive, and green. This is the explanation. But i guss these will be down once again after this upcoming bull run end.
Your ideas and market conditions may not be so applicable to all altcoins. Most market conditions can throw you into a quandary, so it's best to be strategic in picking altcoins. Different market conditions can go through dumping and it's normal to panic investors but it's better to pick the top local cryptos in your crypto selection and check the potential. Ethereum, BNB is the top altcoins in my opinion. Your strategic selection can yield more success in altcoins than in dying crypto coins.