>>2025674>traditional European touring bike buildersA lot of what you're thinking of are Trekking bikes, and are intended as essentially fancy city bike / hybrids. 'European' spec is to go absolutely insane with accessories, chain case, dynamo lighting, fenders, kickstand, etc, and these bikes traditionally are very heavy, 15-20 kg.
Aluminium frame is to make them lighter as they are often ridden unloaded and the weight of the already is insisted upon being ridiculous. The same issue exists for e-bikes, e-bikes need to be light because they are fucking heavy.
This is less a consideration for a true touring bike as the weight difference of the frameset compared to your gear loadout is negligible.
I don't think it's even true though that steel frames are de rigour online for bike packing / touring, as most people nowadays buy gravel bikes to tour on, and the people also intending to ride those bikes unloaded tend to buy fairly generic aluminium / carbon ones. Those aren't even not cool.
For actual touring bikes I don't think it's true either that euro mfg eschew steel, i have seen a lot of modern steel ones.
There is also the factor of what trekking in europe actually entails, a lot of it is on a series of interconnected flat smooth bike paths, you can go all through France and Germany like that for example, and so a nicer riding frame is less important.
