The second person to write a story about a young boy and an escaped slave on the Mississippi wasn't a novelist, he was a typist.
"Just like that hot viral video but different/better/more clever," is extremely different from "that hot viral video."
In more and more fields, the originator of the novel idea reaps an outsize share of the benefits. One reason is that it's easier to gain attention quickly. Another is that once you gain attention and reputation, it's easier to lock in permission and turn it into a foundation for your next project. And most of all, when attention is precious, earning that attention with innovation is priceless.
Yes, there are exceptions for those that bring service or price or reliability along to polish an existing idea. And there are certainly businesses that profit from taking over after the innovator, exhausted, gives up and moves on.
But given the choice, I'd say first is a better use of your talent.