It's hard to answer this in a way that looks like a typical Ask Historians post, as the answer is very simple. I'll try to give as much detail as I can, but it can honestly kind of almost be summed up in a sentence.

Once Iron Working became understood and refined as a process, only very few applications for Bronze remained, the reason for this is that Iron is Cheap, Plentiful and easy to access. While Bronze is Rare, Expensive and difficult to obtain. Not only is there vastly more Iron available in raw tonnage, that Iron is also more easily obtained even without factoring in the scarcity as it is contained closer to the surface and within a singular ore that means you don't have to combine multiple ores from multiple mining sites to make it.

The way that people seem to think of the Bronze Age and the Iron Age was that Iron was some technological upgrade, a harder stronger better metal. A commonly held laymans understanding is that the people with harder stronger Iron Armour and Iron Swords came along and killed the people with softer weaker Bronze Armour and Bronze Swords.

What really happened is that the people who could gather usable metal very easily obviously had a better time than the people who had to manage complex mining operations to find usable veins of both tin and copper (sometimes not so conveniently located in close proximity to each other as they'd hope), and then combine those materials to create Bronze and so once they were shown how to use Iron they mostly chose to do so.

There were in fact applications for Bronze long after Iron supplanted it as the primary metalworking resource. Bronze is in fact Stronger than Wrought Iron and not as Brittle as Cast Iron and so for certain applications despite how much Iron's accessibility and Usability factors caused it to be dominant Bronze continued to be the primary choice.

An example of something that seems counterintuitive to the people who have the Bronze Swords>Iron Swords straight technological videogame style upgrade tree view of the history of metallurgy is that Cannons tended to be made in Bronze most of the time as Cannons developed as a technology. While the average person raised on a popculture diet of history sees history as basically going Stone>Bronze>Iron>Steel>Guns in a fairly linear way is surprised to learn that people were preferring Bronze for their Guns due to its superior qualities. It is far more common in history for technological innovations and new techniques and materials to be added on top of and combined with existing materials and techniques expanding our repertoire of options, rather than replacing them entirely.