It’s been discussed many many times and experience shows (even from the biggest authors on here) that right or wrong, more creative does not sell as well as the common style.
Aside from that these are not intended to be out of the box complete sites - only building blocks that should be customized and edited to be uniquely suited to the project.
Anyone who wants heavily creative or individual should be avoiding stock marketplaces which by their nature will be less unique, and instead seek custom developers or designers.
For example many of those that you see on inspiration sites (awesome though many are) look very distinct because they are a completely different proposition to what makes a stock site successful i.e. versatility, options, flexibility and so on.