There definitely are, but speaking totally personally, great bits of art really made D&D enchant me in a way other games did not, back in the day. I am an artist - much of my A-level art project was inspired by DiTerlizzi's Planescape work, so I get that this isn't broadly applicable, but it mattered to me that 2E employed some amazing and risk-taking artists, and I feel like Wotc has been on the safe but not amazing train with D&D and they can do better. They can take risks. They can shock. Being boring is a bigger sin, IMHO, than being controversial or even disliked. I don't like Jeff Easley's work, personally. It does not appeal. But I can see the artistry and style and I remember it. But 5E art? Pfffff. And it's not age or the like. I can envision some other contemporary TT RPGs far more easily (and contemporary MtG, even though I don't play that!).
Maybe that just me though!
No, I agree, even as someone who can only draw what's necessary to work in Geometry, I have a great appreciation for art. However, I would even venture to say that 5E's art is not just consistently good/middling, it is hinged on a weird sort of strategy. I mean, consider this:
1. The cover art of 5E books is generally a bit more exciting than any art piece within the book itself. It also happens to be higher in definition. The quality of the covers has varied, but, generally, they're memorable. I have a pet peeve with the cover of the PHB, but that may just be me.
2. The art attached to monster stat blocks is generally rather sharp, which is something I like in D&D art. It usually has good definition, stylish artistry, and a nice look. This is probably an intentional investment, as monster art is used by DM's (and sometimes players) to visualize monsters.
3. The rest of the art, unless it's a character portrait, varies wildly, swinging from weirdly impressionistic and strangely proportioned to evocative. However, the splash art seems to be, overall, homogeneously forgettable. All of it is done in watery oil pastels, and there doesn't seem to be much in the way of planning in these pieces.
Am I right, am I wrong? It may be just me, but this is something which I have noticed.