Lots of abandoned coin coins, usually crypto developers only develop crypto at the beginning of the beginning of the release of the platform, but if the platform is successful and popular, then the coin will also triumph.
The value of coins depend on how successful it is being implemented in the market for it to be valuable every time and give profit when you keep it for long time. But there are project that coins never been even listed on the exchange for you to earn from it, and that what make us sad. Coin that became successful development can live longer with value and can be expensive in time and better to keep coins that is successful for it to be worth of holding.