What dead crypto currencies do you know?
What are the possibilities for crypto currencies that almost can't be exchanged any more?
Do you have any ideas how to make money on big amounts of abandoned cryptos?
I think there is no solution to this problem, only the one who can answer is the developer of the coin. The solution lies in those who develop coins. Do they want to develop further or not. Because if you sell no one buys, or someone buys at a low price. I think selling at a low price will be better than holding you without meaning.