Irrelevant metrics. If it takes me seven days to make crap, and it takes someone else three days to make something nice, and it takes a third person 20 minutes to make something gorgeous, then the best art is the one that took 20 minutes. If it then takes me 20 minutes to belt out something nice using a lot of shortcuts, then that is better art than the crap that took me 7 days. Who cares about the shortcuts if the end result is better than it would be without them? Or if I take 7 days of trial and error to produce something that, in the final take took me 20 minutes, then all that matters is whether the final take is crap, nice, or gorgeous. Not that the final take took me 20 minutes or that the whole process of getting to that final version took me 7 days. To some extent talent doesn’t matter either. Yes, the more talented artist will probably produce better art, all else being equal, but when is all else equal? The more talented artist is just as likely to churn out more, faster, as churn out better, equally often. So if I can turn out something gorgeous in 7 days and someone else can turn out something gorgeous in 1, who cares? The only reason to care is that the more talented artist can churn out 7 times as much artwork, which benefits us all, and maybe make a living at it, which certainly benefits the artist and long-term benefits us all. The best art is the one that produces the best feeling from the final product.
But what feeling is “best”? When the artists are not going for gorgeous in the first place, because they want to make a statement where ugliness is more appropriate to the message and feeling they’re trying to create, then the ugly crap that got its authentic 20 minutes in Paint look from literally being put together in 20 minutes in Paint is better art than something nice. As Picasso said, it took him several years to learn to paint like an adult, but many more years to learn to paint like a child again. Or do you think it took Robert Mapplethorpe months of work to shove a whip handle up his yay, squat, and take what’s probably the most celebrated picture of his career? Or how long do you think it took Andres Serrano to take a yay! in a glass, drop in a little crucifix with Jesus on it, and take a photo? That they had the idea to do those things, and then actually took a picture, is art. How long it took them is irrelevant. Leonardo da Vinci’s work isn’t worth more because he was painfully slow and indecisive while creating it. It’s worth more because the end product was generally amazing. But Michelangelo’s work is equally worthy because it was also generally amazing, and it’s not worth less because he was faster at it than Leonardo. But Salai’s work is worth far less than Leonardo’s because while he was technically competent (some of his paintings and Leonardo’s have caused a lot of confusion as to which of them was the actual artist), the ideas behind most of Salai’s works were Leonardo’s ideas.
So the value of art is a combination of the idea behind it (which can be instantaneous, and indeed takes less time the more talent there is behind it), and the execution of that idea (where there is no linear relationship at all between talent, time, and quality). Mapplethorpe isn’t for everyone, nor are Hoihoi or Nezumi. Leonardo da Vinci and Michaelangelo generally are. Some people really appreciate Datte’s or tg-0’s style, and others, while not _dis_liking it, find it too cartoony to take it seriously. Etc. Popularity doesn’t mean something’s better, and lack of popularity doesn’t mean it’s worse. Nor does how long it takes or how much effort went into it. What matters is how the final product comes out, as rated by its intended audience. Basically, the only rating that matters is when it’s rated by people who like (or at least appreciate) the genre the piece is in, comparing it to other works within that specific genre.