I understand that steel is far superior to bronze but given that early Iron Age tools and implements and weapons were not steel, how much of a technological jump was iron really? Did iron displace bronze purely because it was the superior material ? Or were there factors such as loss of international trading networks which made bronze harder to make etc?
Early iron wasn’t massively better than bronze, though it’s worth mentioning that the exact quality of bronze varied, as the exact balance of tin to copper changed depending on regional preferences, availability, and intended use. The quality of early iron varied a lot too, until techniques had time to standardize and spread.
The biggest difference-maker between early iron and bronze was availability. Like you mentioned, bronze required healthy trade networks since few nations had direct access to both copper and tin. The composition of bronze artifacts shows that a lot of them were made out recycled bronze that had been melted down and repurposed, which would make sense with bronze in short supply.
Iron ore was more abundant than copper and especially tin, so it was usually either locally available or easy to find nearby. Not to mention needing only one type of metal massively simplified trade.
Additionally, while early iron wasn’t significantly better than bronze, as ironworking improved that gap widened. By the time trade networks recovered from the Bronze Age collapse ironworking had advanced to the point where it was a better material than bronze outside of specialized uses like ship fittings, coins, or statues where rust and corrosion would be a big factor.
Did iron displace bronze purely because it was the superior material ?
Not at all. Generally, bronze was superior to iron for most purposes. The bronze alloys used over much of Eurasia for weapons were of similar, or slightly higher hardness, to iron, and even harder bronze alloys (with more tin) were used in East Asia for weapons.
Bronze was easier to make. Lower furnace temperatures were needed, so it was a lower-tech process. Iron smelting (i.e., turning iron ore into metallic iron) needed high temperatures, but until the introduction of the blast furnace (long after the start of the Iron Age), the ore-to-iron conversion happened in the solid state, since the temperature in the furnace was lower than the melting point of iron. As a result, the iron was made in the form of a spongy "bloom" consisting of a mix of slag and metallic iron, which needed further working by repeated hammering and folding to produce a usable product.
Bronze could be cast, making it easier to make very complex objects. Bronze could be cold-forged, making it easier to make thin sheets (notably, bronze helmets continued to be made well into the Iron Age).
Bronze is corrosion resistant.
Bronze can easily be recycled by melting it down.
The main physical disadvantages of bronze vs iron are that it is denser (about 13% denser), and is less stiff (so bronze items need to be a little thicker to be as resistant to bending as iron).
how much of a technological jump was iron really?
Iron wasn't a technological jump in the sense of producing a product with better physical properties. It was, eventually, a huge economic jump. Compared to copper ores and especially tin ores, iron ores are very common. Some iron ores, most notably bog iron (lumps of iron ore formed by bacteria in wet conditions such as swamps and along rivers) could be obtained without needing to mine through rock.
Once iron-making technology became common, this made iron significantly cheaper than bronze. Iron widely replaced bronze because it was a cheaper material, even if somewhat inferior for most purposes. This "replacement" is perhaps more of an addition than a replacement - bronze continued to be made and used (and recycled) during the Iron Age. Essentially, more bronze was used in the Iron Age than had been used in the Bronze Age, but the amount of iron was even greater.
Once steel was developed, and the methods for making it and using it (e.g., hardening through heat treatment) were understood, it was greatly superior for many uses. However, even into late Medieval and post-Medieval times, bronze was still used as the superior metal for many purposes (e.g., cooking pots, cannons), with iron or steel as the cheap-and-nasty alternative.
For a longer and more detailed discussion, see my past answer in: