Wow way to destroy the premise of your own article with the first graph.
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Hm...yeah, i don't know. If you just look at the narrow window of the last five years, they may have a point.

But if you look at the larger trend since 2000 you can just see this as another temporary dip, which as we can see in this graph is something that happens occasionally even while on a steep upward trajectory. It was to be expected that we would see such a dip in the immediate aftermath of Covid, just like there was a dip following the 2008 Recession.
Of course you could also argue that even over the long term the growth sort of looks like it's starting to slow down and the interval between dips is getting shorter (the second part would not be related exclusively to steel but to global crises of capital happening more often). But even then, the long term trend still looks like it's growing, if less rapidly. That's not a peak.
There would have to be a pretty abrupt end to growth to suddenly lead into stagnation or even decline, and that generally doesn't happen unless something catastrophic takes place. And the world will still need steel for a long time to come. There are plenty of countries that will need huge amounts of it if they are to develop to the level that China or the West have.
That being said it's also natural that there be an end to the growth at some point. It's impossible to grow forever. Most of the growth in the past 25 years was driven almost exclusively by China. Eventually one would assume that China reaches a saturation capacity beyond which it does not make sense to further increase production. At that point it's up to other countries to develop their own productive capacities if global output is to keep increasing.
I am not well educated enough about the steel industry to say how close China is to that point, but my guess is that they are not yet reaching it in the near future. Iron is very abundant. And with the kind of massive expansion in energy production that is happening in China, they will be able to introduce new methods of steel manufacturing that rely on renewable electricity rather than fossil fuels.
I think the key part is that it's not evenly distributed. Most of the production is happening in China. It would've been really good to separate Chinese steel market from the rest in the article.
However, the thrust of the article is that the global economy overall is slowing down. So the expectation for steel production to slow down is based on the lower demand going forward.
There is no reason to assume that any major dip won't just be a lull period between China's slow down and the rest of the global south's move into high gear on their 3rd wave industrial revolution.
There might be some new material that makes steel less necessary in the future but until then there's like half of the world that has a lot of catching up to do and they will use steel to do it.
I think that's the most likely scenario myself. China's whole economy is basically built around being the world's factory, and it's in China's interest to help global south develop because they can export their infrastructure building skills there.
The situation in the west, on the other hand, is likely to be quite different. Western economies are headed for the abyss, and I can't really see how liberal economics can find a way out at this point. If the US suffers a major crash, the rest of western economies will follow, and I can see USSR style collapse unfolding where it will take decades to recover after.