It is an oversimplification to say that all of the Bronze Age powers fell, let alone in the same way and for the same reasons. Rather, each of the Late Bronze Age states went through its own transformational process in the 12th/11th centuries BCE. The southern half of the Hittite empire gradually splintered into smaller kingdoms – the so-called "Syro-Hittite" or "Neo-Hittite" kingdoms – whereas Assyria went through a brief period of decline and contraction before expanding once again in the Neo-Assyrian period. Egypt experienced decline, political unrest and civil war, and gradual decentralization before fragmenting into smaller kingdoms (the Third Intermediate Period), although unlike Ḫatti it was later reunified. Many Canaanite (or "Phoenician") cities like Byblos seem to have been scarcely affected by the end of the Bronze Age and survived into the Iron Age thriving and intact. Cities and palatial centers on Cyprus were variously abandoned (e.g. Hala Sultan Tekke), shifted location (e.g. Enkomi to Salamis), or survived more or less intact into the Iron Age (e.g. Paphos), and Cyprus seems to have gradually transitioned from a unified Bronze Age kingdom (Alašiya) to the competing Iron Age kingdoms known from Neo-Assyrian inscriptions, although this transition is still poorly understood.

u/UndercoverClassicist discussed the collapse(s) of the end of the Bronze Age in Did people realize they were part of a civilizational collapse during the bronze age collapse?

I touched on the end of the Hittite empire in How did the civilizations fall in the end of the Bronze Age? and more recently in When and how did we learn that the bronze age had really collapsed and was a thing and not just an imaginary folk idea like Atlantis?