Most discussed possible causes for Bronze Age Collapse are
- Climate change
- Droughts (either natural, or caused by deforestation)
- Volcanic eruption
- Sea People
But Bonze Age Collapse is also begining of Iron age. It seem rather obvious question to ask if the main cause was the iron itself?
At high-shool I heave heard that Dorians who invaded Mycenean Greece and Crete were equipped by iron weapons. But I never saw this discussed more broadly in context of Bronze Age Collapse in general (Egypt, Hittite, Assyria ...).
Were military and socio-economic changes caused by spread of iron technology (similarly as European colonialism and industrial revolution, end of feudalism are strongly connected to technological disruption and caused collapse of large empires - Ottoman, Mugdal India, Qing China ... )
I don't speak so much about iron weapons being superior to bronze weapons, or about invaders (sea people) heaving particularly good iron weapons.
What I find more reasonable, is to consider that centralized power-structure of these societies was build around control of these rare resources (bronze,copper,tin). When iron started to spread, they loose "monopoly on power" and failed to adjust.
The conection of Broze age collapse with ironworking is discussed to some degree https://en.wikipedia.org/wiki/Late_Bronze_Age_collapse#Ironworking
Nevertheless, considering how obvious this question is for an outsider (i.e. not profesional archeologist or historian) I would assume, historians would spend more time explaining why this is not the primary hypothesis.