I don’t think that using salted butter is bad, if there is a reason for it, but I think the way it is advised as a substitute for unsalted butter doesn’t often acknowledge what it does or the flavor it lends. And since salt content varies from brand to brand in a way that is hard to test or measure, it also cedes control.

I think that understanding how ingredients work together, what is hidden and what is amplified, even by “neutral” ingredients is a big part of leveling up baking skill