That's really true, not all tokens/coins will recover when they are bear, even many of them become worthless and uninteresting. it would be better if you only invest in tokens/coins that are ranked in the top 100 market cap.
Back then many of the altcoins had crazy bull runs and went up in value by 100 or even 1,000 times. Investors were blindly pouring their money in to altcoin projects, without doing the slightest bit of research. The thinking was that if they invest in 10 different projects, at least 2 or 3 would return profits. That worked in 2017, when the success rate was around 20%. But in 2018, the success rate dipped below 5%, and many of the projects were overpriced to start with. That meant that even if a project was successful, the profits were not large enough to cover losses from the failed projects.