Most of altcoins have nothings special and people do not need those altcoins. People just need those coins products and holding these altcoins will help investors get profit base on product succee.
You are absolutely right. Most of the altcoins have nothing special and a lot of them are actually useless. But we don't know which project will be successful and which is going to be failure. We can say that most of the altcoins are useless now, but not when they were made it.
With altcoins, we can earn 100x. And bitcoin will only grow 5x.
Having a small deposit you need to invest in new coins that would increase your money