Like with everything it depends… Simple decks like the one you are showing, or red dots for example, are a bit to minimalistic for me. But there are others that I really like (cherrys or 1st epc by chris ramsey for example).
Simplicity is awesome but it has to be above a certain threshold.
With detailed art its pretty much the same. There is a point where you can “overdo” it. Buuuut I think in general I tend to find detailed cardbacks more interesting.