Altcoin is an imitation behavior, imitating famous projects, just changing some parameters and then re-publishing, because they have no constraints after obtaining the investment, and they are guaranteed by their own morality, so the basic use fails
that is only half the problem! and it concerns only a certain percentage of altcoins.
but the main problem which concerns all of them is the fact that the purpose for their creation has never been to solve anything real. for example we call them crypto "currencies" but none of them are "currencies". the developers never intended them to be currencies either. they wanted to make something that can generate a revenue for them so they focused all their energy on earning money. which is why the altcoins all suck!