Anyone can make up coins but why is anyone even buying any of these? If dogecoin has no real use... then none of those other coins have any use. So why do these new coins keep showing up?
Basically this is all because cryptocurrency is used as an investment.
Unfortunately, this is a method used by irresponsible people.
An example is when Dogecoin goes up high, everyone will think it's impossible to reinvest in Dogecoin at a high enough price.
Then the bad guys will appear offering projects that will compete with Dogecoin at a low price initially, therefore there are always new cryptocurrencies usually to take advantage of immediately, but I think this is an unfair way because the first entrants and token makers are the ones who benefit. The one who enters last will pay for everything.