In reply to Emil.

immediate usability or functionality of a newly purchased product

No theme fits this description. 🙃

Most require setup or additional steps to make a site into a site. Semantics aside, I'll put it this way: there's not a single theme on the market that does not require additional steps to make a site look the way it's intended to look by developers. And everyone knows this. That this is a point of contention in a niche theme review is silly.

That's why demo content and instructions exist. And it's also why default content on the .org site makes most themes look awful - because they weren't built for demo or one-size-fits-all content.