There are functional aspects that go beyond those you consider though. For example, rounded corners are, from a functional perspective, unnecessary (and maybe e

There are functional aspects that go beyond those you consider though. For example, rounded corners are, from a functional perspective, unnecessary (and maybe even confusing! Are the corners clickable?), but it turns out there's actually a bit of psychology and evolutionary weirdness that make humans more comfortable with rounded corners than sharp ones. Other sites have marketing needs. They might colors or motifs to evoke positive associations with related brands. Or avoid negative associations with others. Or just to avoid looking too much like a competitor. A lot of this is hard to articulate for most. Heck, even some designers can't explain why another design feels right and another doesn't. It just comes across as "that one looks nicer". But there are often (though certainly not always) deeper, functional purposes behind what seems to just be an aesthetic.