I think the word “prolific” applies to what TikTok facilitates, much more than the word “creative.” And personally I find the amount of word for word and beat for beat mimicry on the app maddening.
Citing dictionary definitions just shifts your argument from one word whose meaning you didn't define to another word whose meaning you haven't defined. Is the Mona Lisa original? It's not the first oil painting, nor the first portrait, nor even the first painting of an Italian noblewoman made in the renaissance style. Yet it's commonly considered to be creative despite being imitative and unoriginal in all those previously mentioned aspects. What definition of original can you then make that simultaneously includes the Mona Lisa, is mutually exclusive with any imitation, and excludes the "majority of humans".
Of course people are going to be outraged over the statement. You're playing a semantic game where you came up with your own definition of creativity that excludes what most people do, and then not actually defining it or justifying it. If you used a more common definition of creative you'd have no argument to make.
Novelty isn't the only thing that makes something creative, a string of randomly generated numbers is always novel but wouldn't be considered creative. Creativity requires novelty conveyed through recognizable patterns, which means some amount of mimicry has to be involved.