Gas masks deal with CS gas (I find it ironic that CS gas is banned by the Geneva conventions, but using it against civilians is fine).
Goggles reduce the chances of eye injury due to debris, rubber bullets, police batons, etc. A decent face mask extends this protection to the rest of the face.
Soft, expanding bullets stop more easily when they hit something. Full metal jacket military bullets penetrate things like auto bodies, walls, etc, and pose a greater threat to innocent bystanders.
Plus, the real reason is that in war, wounding the other side is better than killing, since the wounded have to be treated, evacuated, supported, etc., and their presence is demoralizing to the enemy.
Its an offence against the Geneva convention, NATO militaries are worried they will be accused of war crimes if they introduce bullets that could be considered dum dums
Actually the 1899 Hague Convention, and the US is not a signatory. The US reserves the right to use expanding bullets when there is a clear military necessity. Until 2010 the prohibition only applied to warfare between military units, not to combat with irregular or civilians units. https://en.wikipedia.org/wiki/Expanding_bullet
Goggles reduce the chances of eye injury due to debris, rubber bullets, police batons, etc. A decent face mask extends this protection to the rest of the face.