Every new cryptocurrency project has their own reasons, you can read it on the new cryptocurrency website or you can directly ask the team directly from the new cryptocurrency.
and some reason does not make sense, and tends to exist to make a project.very rarely projects that can really be implemented in real life.
there is always a reason to make something new, and of course the reason is to replace the old one, cover up the old shortcomings, or make an altcoin with a new goal. well, even today, there are still many people who design this development.
as long as has good purpose is not matter with us.but some developers make to easily get money from cryptocurrency market.although build fake project.as we know today no good project anymore and most of them was useless.