The difference there lies in the durability and weight. I will go with your Jadeite vs bron for comparison. Jadeite has about 2/3 maybe 3/4 of the durability of Bron. But there is a reason why bronze age swords were quickly replaced by iron and later steel. Even the Maori people of New Zealand used Onyx and shark teeth for weapons in their history, but as soon as steel was introduced they switched to it because it was better. Yes Jadeite is cheap and easy to get, but doesnt mean you want to use it for every weapon or every tool. If you do a lot of PVE farming or dont die every fight in PVP you tend to want your weapons to do the same damage in prolonged situations. I often use Bron clubs for that reason, it is cheap and it has REALLY good durability for that tool. Same reason why you see copper and brass hammers in tools to this very day.
Even in reality sometimes harder to make doesnt mean better. Brass is not better than bronze for some applications... Steel isnt better than aluminum in other situations. Right material for the right job.
Yeah, I mean, I understand all of that, my point is more from a gameplay perspective it would be nice if it was organic-mats>t2 metals>t3+metals, due to the difficulty & time sink of actually making t2 metals.
Anyway, it's a game so real life comparisons are not that applicable and are just for fun, but you can't be telling me that obsidian holds an edge better & is better for arms and armor than masterwork bronze or copper alloy/brass? Because that's just not true.
As far as 'bronze age swords quickly replaced by iron', that's actually a common misconception. People have studied this extensively, and masterfully made bronze arms are actually marginally superior to early iron weapons until you get widespread bloom furnaces & steel into the medieval period (which we might compare to steel, or, in its later & higher quality period tungsteel). The reason iron was actually adopted was due to trade-networks/logistics; you could easily outfit a large army in iron vs. having to find rarer tin to make bronze from copper. When the late bronze age collapse occurred, bronze age copper & tin trade-networks dried up fairly universally.
You get a lot of people who are not master bronzeworkers like bronze age smiths making shitty bronze weapons and then using fairly good modern iron & techniques and surmising that iron is 100% superior to bronze right out of the gate. In actuality, historians of the period are pretty unified on their view that early iron age arms & armor made of bronze were superior in functionality to early iron age arms and armor made of iron. It wasn't just 'fashion' that Ancient Greeks, and even the Romans(just to name a couple), continued to work with bronze long after iron-working had become commonplace.
Basically, bronze gets shit on a lot because it takes a lot of artisanal skill to work it properly, and most armaments made from it today are not made by master bronzeworkers(which makes sense, since we have relatively easy access to high quality steel, and so most people specialize in working it instead). High quality bronze tipped spears, for example, can even puncture sheets of iron (and there is proof of this on youtube). People wouldn't have kept using it if it didn't do a fine job.
Again, none of this really matters, since this is ultimately a fantasy game and not a simulation of the real world... But to continue the comparison for the fun of it, cuprum is superior to bron in the game. There is absolutely no argument for copper being superior or even comparable to bronze in any kind of arm or armor. Bronze is copper's big brother, and is superior in every way.
With all of that said, I'd even take having cuprum get a mild nerf if Bron could get a big buff and bring it up to just below steel. I think it would be a good gameplay change, even aside from the real world comparisons, which are just for fun. I don't think bron getting buffed up to, say, between jadeite and steel, would be a negative change in any way gameplay wise... Why does t2 have to be relegated to purely niche roles? What exactly does this add to the experience, beyond making refining a slog?
but with plentiful supplies and no need for gold then I can see how perspective changes.