As a brewer, when you use local ingredients you quickly learn it’s not bollocks. My local malt (which I don’t particularly care for) has a very specific flavor profile and color.

As an even more basic example, go hunt down some New Zealand Cascade hops, or have a beer brewed with NZ Cascade. It is not the Cascade you are familiar with. Terroir absolutely does play a factor. It’s why Nelson (now that it is “open source”) grown anywhere else will not taste the same.