I think the real term is "Not Invented Here Syndrome".
This site has thousands of open sourced game assets: https://opengameart.org
Here is an asset pack of 65 fantasy icons for $5: https://assetstore.unity.com/packages/2d/gui/icons/fantasy-r...
I suspect someone spending $200 and a day of searching could probably find most of the art needed for Queen's Wish. There's really no need for him to be hiring freelancers in the first place.
You can't make everybody happy. JV is going to more reliably make money by making his audience, like me, happy. Why should he change it?
It's a full-time job to find this art in the first place, to resize, to animate, to recolor, and apply effects to the art to help it match your desired aesthetic. And then it still is never good enough.
There's a lot to be said for having someone produce art to your requests in a consistent style, even if the quality of the art is not extremely high.
Simply saying "just buy cheap assets" completely misses the point here.
When you change your focus from a loyal customer base and change key aspects of your product they prefer in order to chase a competitor's customers you risk losing your own base and still not picking up a substantial portion of the rest of the market.