Not just a copy of Dogecoin, but it is a memecoin and a Shitcoin. Let's forget the fact that it is a copycat of Doge, like the puppy one. Let's just look at it as a coin with no real use case.
And, YES it is fundamentally no value at all, but hey people are actually chasing what they think they can give them a good and easy way of profit. Thus, that's the result of riding so much with the hype, it TEMPORARILY made a few cents. As much as I don't want to believe, but Shiba could still run a little longer as people are still buying it and made it to the top coin. Plus, it's being consistently hyped up by many.
It is true that when it comes to meme coin there is nothing which backs their existence and for the most part those coins only have one function, which is to speculate with them, and since enough people have been convinced that they can use those coins to increase their wealth they remain in the market despite how useless they are, so until enough people recognize the truth those coins will continue to exist no matter how much we may disagree with it.