I’m no vexillologist, but I prefer the trapezoid. It means the flag can be constructed entirely out parallelograms. With a triangle though, you need to use an ugly concave pentagon.

I really like Kuwait’s flag. It’s bold, and it looks a bit 3D.

I don’t think it looks great when some other device is superimposed on the trapezoid like in the other two examples you give. I generally don’t like things superimposed on triangles either, though.

I agree, triangles generally look better. The trapezoids always seem clumsy

While I prefer triangles, the trapezoids still look nice. And like you said, they make them more distinct from other flags.

I think one vexologist said to another “we should get rid of these triangles” and the other said “just the tip.” And now we have some trapezoids.