True. But it keeps happening.
Be it two thousand years ago or 500 years ago. Sexy armor proves that humans haven’t really changed.
Kings and generals don’t really find themselves alone on the front lines. The armor is nearly ceremonial, no one is supposed to take a shot at the king. Even if the king were expected to visit the front lines.
As such, kings, princes and other nobles never had practical armor. It’s all armor-fashion and status symbols (including sexualization, when said sexualization was in fashion).
That’s just called 1600s era half plate.
As halberds and other armor penetrating weapons became normal (and Guns), the focus of armorers was on deflection rather than outright stopping blows.
Also, iron became cheaper and thus mass produced. So in some sense armor got worse, but far more people were wearing armor. The small bits (gloves, legs, etc etc) couldn’t be custom made per person anymore because of mass production templates. But armor was well on its way out by then anyway as guns were obviously the future.