The Sea Peoples almost seem to have been the Huns of their day. Great and once invincible empires fell or declined and a dominant military technology was rendered redundant. The old palace culture was destroyed because the charioteers who benefited by it and protected it, could no longer do so.
Drews, a scholar well worth reading, thinks that the Sea People infantry could match the chariots because they were equally well armed and armoured, swift moving and quite prepared to take the fight to the enemy. There were also relatively speaking lots of them.
In his view their armour reduced the effectiveness of the composite bow, forcing the charioteers to come to close range, the infantrymen then surged forward seeking to kill the chariot horses with javelins, and then despatching any stranded charioteers by virtue of equality of skill and equipment and advantage of numbers. It’s a compelling vision.
Against the old order’s infantry, the Sea Peoples were invincible, only the Heroes could match them in skill and arms and there simply were not enough of them.