On a forum for writers, in a discussion about a member's design for his publicity material, one person commented on a sample using Cinzel for secondary text that it should use a serif font to contrast with the main heading. I responded that Cinzel IS a serif font.

The person then came back with, "Point. But it's overused."

? ? ?

As far as I know, Cinzel has never been included with Windows, MacOS, Linux, Android, or iOS. I've never met anyone else who has even heard of Cinzel. Am I missing something? Is Cinzel so widely used in some circles that a person would be justified in calling it "overused?"

If you flip it around and ask “name some overused fonts”, it certainly wouldn’t make the list.
But it all depends on context. Google fonts are used millions of times every day and it that sense, it is certainly used a lot and probably also a common choice for books. I have certainly seen it on covers in certain genres. Or one could mean the general style (roman caps like Trajan) and that is indeed overused.

Thanks, Ralf -

The comment was in response to a business card design and the author specifically identified the font as Cinzel, at which point someone else chimed in with a comment that the font should be a serif font to contrast with the main heading. I responded that Cinzel IS a serif font.

The person then came back with, "Point. But it's overused."

So he/she was clearly stating that Cinzel is overused, not just that serif Roman text is overused. And I was, quite honestly, shocked, because I could not have considered Cinzel to be overused at all.

Some browsing in the fantasy genre …