Why did gunpowder make armour less useful in European warfare?

The development of gunpowder and the subsequent improvement of hand firearms, such as the musket, rendered traditional plate armour increasingly ineffective in European warfare.12

As firearms became more powerful, armourers were forced to increase the thickness of metal plates to stop projectiles, which significantly added to the weight of the equipment. Eventually, this created a practical dilemma: to provide sufficient protection against modern weapons, the armour became so heavy and cumbersome that it severely restricted the wearer's mobility.13

By the 18th century, plate armour was largely abandoned for infantry use due to a combination of its high cost, its inability to reliably withstand contemporary ballistics, and the tactical necessity for greater speed and maneuverability on the battlefield. While some elements, such as breastplates, remained in use for specific units like heavy cavalry, the era of full-body personal armour effectively ended as military focus shifted toward professional, mobile, and disciplined formations.12