Honest question: do you think art’s value is proportional to the time it took to create it? Like a painting that took hundreds of hours is necessarily better art than a minimalist work that might have taken a few hours, or less?

Not op but I don't think it's proportional, it's more like an extra layer of value on top of the creation's innate value.

No, I think the value is in how much of and how well the human experience is compressed into the work (and how well it decompresses in the mind of the beholder).