Are you sure your question is correct? Because it is not chronologically logic. The implementation of the phoenician alphabet happened around 200 years after the collapse of the Bronze Age (c.a. 1200-1100 BC).
The collapse of the Bronze Age was one of the causes for the creation and success of Phoenician commerce, activity by which this civilization is famous for. It is not clear why, but around 1200 BC many civilizations ended abruptly. This vacuum of power created a new independence for many cities which made possible a new commerce system. Phoenicians traded with Mesopotamians, Greeks, and Egyptians. They had trading routes that reached Spain, the Atlantic Ocean and Britain. Trading lead to intercultural exchanges, so Phoenicians knew many types of writing, which they simplified to create their own alphabet (c.a. 1000 BC) based on sounds instead of symbols.
The Phoenician alphabet was used to organize their colonies and trading contacts on the Mediterranean region. As this alphabet was simpler, writing was no longer limited to clergymen or scribes. It also influenced Greek alphabet which inspired the latter roman alphabet.
