Wow, I thought by copycat you meant that they went for a similar feature set, but from screenshots it looks identical down to font and color choices. Are they just running a white labeled instance of Plausible’s OSS?
A lot of relatively new analytics services tend to have similar looking frontends these days I've noticed though.
A good rule of thumb: if you think something is original, chances are it’s because you’re just not very familiar with the space.
Ultimately, none of this matters. The goal of a product should be to help customers achieve the outcomes they want, not create something original.