Sorry, this might come off as obtuse, I don't mean it that way. Perhaps I'm misreading your title, but I find it odd that a UX designer or product person would be the one writing proofs of concept that require a database.

Unless you mean for solo projects? In that case, it may work for you, but if you're not a database expert, it makes sense you would work around your limitations. That doesn't necessarily mean it's a best practice.