From the pictures it looks like there are parts that show real care but other parts that are kind of messy and maybe more half finished projects.
It seems possible, if not likely, these were unfinished pieces that were in-progress when the artist died. Perhaps many of these would never have been finished no matter how long the artist lived. You might look at one and see what had gotten a lot of attention and what hadn't, maybe even see what had gotten attention first and what later, and wonder about exactly why. It's pretty interesting, IMO.
Probably one good way to value art is its impact on the viewer. So that's obviously very subjective. But surely a variety is good. Or put it this way... the skillfully and richly crafted masterworks that you view in a museum are certainly worthy works of art. But if skillfully and richly crafted masterworks that you view in a museum are one of only a small set of forms of worthy works of art, you're putting art in a small, confining pen. That would really limit the impact it can have. Which, I think, means that's just a far too limiting a view of art.
We have "HODL" which is a cultural phenomenon, which itself is a typo.
We have numerous memes images of cultural significance which is made with very low production value because their original makers had a great idea but not very good image editing skills.
I don't think that "production correctness" or "precision" is a metric that art can be evaluated on.
A cultural phenomenon is not art in my opinion. I think things can be made by people and found interesting and well liked without them being art just as a natural phenomenon can be interesting and well liked.
Of course there is modern art where it can seem like anything can be considered art but even in those cases there is often work and talent involved. Maybe it's through the selection of which works to make public or the storytelling with the art pieces or coming up with new experiments.