And add it to what you have said, there are also some factors involved in the dead of a coin and they, the developers are not truthful and they are scammers. And once people notice that the developers are scammers then nobody will be interested to invest in that project because the fear is they will be scammed and for that nobody will have that interest to invest in the project and if anyone invest in it others will discourage him.

Then another thing that can make a project to die is the Market Cap and the value of the project. If the market cap is not good enough, people will not even look into it and the community support/the population of the project also determined the crowd of investors attracted to the project. Example, NOTcoin is one of the popular token in the cryptocurrency market.