In my opinion, if the old coin is from an ICO project, then it is not worth buying and keeping for the long term. Many coins from ICO projects do not survive and are of no value in the long term because they do not have strong fundamentals. Some even went missing on the exchange after a few months.
To be specific too, there are many ICO projects that became successful and are now established in the market and those ICO projects from 2016 to 2017 were mostly the successful ones.
But to those that have started to run their ICOs on the period of 2018, that was the year where most of the ICOs were a failure. It's due to the scams and people got fed with the pump and dump scheme that has been common before that period due to some influential people that's also happening right now. To those that have went missing, it's the exchange's decision to delist them if they find them no longer liquid.