If that's about americano, James Hoffmann[0] covered why this might be the case - normally you use the steam wand to provide the water for the americano but that water has been sitting in a tank being heated and cooled and gradually evaporating down to concentrate all the bad stuff. If you use the wand to steam fresh water, you don't get all the crud. Seems simple and logical enough.
[0] https://www.youtube.com/watch?v=0HdzJz_evNw (skip to about 5:00 for the explanation)
Although surely you would need to make the steam from steamed steam for optimal results?
Well, it's a complex question. I'd suggest to start from plotting your favorite coffee hardware brands and barista youtubers/tiktokers over the phase diagram of water, and continue from there.
Once you get comfortable with thinking about coffee in Scientific Terms, one avenue to explore is to try and embed the aforementioned phase/opinion water diagram plane into the larger Great Material Continuum hyperspace. To do that, you add a third axis: price (for hardware obviously by MSRP/catalog price; for vloggers, plot specific tips or steps by price of ingredients they use).
Having done that, you should have all the tools needed to make informed decisions in this space - just compare the paths water takes through this enriched 3D phase diagram as it turns into steam and then your beverage using any given method and combination of equipment :).