It's not very different. I don't know if "flat" was ever the right word to describe the look it started moving toward post-Aqua; I think I'd be more inclined to

It's not very different. I don't know if "flat" was ever the right word to describe the look it started moving toward post-Aqua; I think I'd be more inclined to call it "minimal", occasionally to a fault. With a few exceptions (most notably the bonkers choice to make all keyboard shortcuts gray in menus so at first glance they all look disabled), though, I mostly like the look that Big Sur's ushered in.