Kind of the difference between a guide fly and one you might tie yourself. Guides and professional anglers through the years have done a nice job cutting the fat from the tying and fishing process. What’s the bare minimum needed to be the most effective at putting fish in a net.
I tie a lot of bare minimum type flies like the super simplistic green buggers I fish a ton for SRC and in lakes. The clousers I fish for coho are pretty basic too, though someone responded to me once that all you need is a hook with some red thread on it to catch coho. That may be true but my confidence would be in the toilet fishing them so for me, my super basic clousers are my bottom.
I also tie a lot of flies that look cool to me (not compared to the super talented tyers out there though) that boost my confidence and I have fun tying. Many of the materials are probably not needed and they are more complex than they need to be. I enjoy playing around though by tying something funky on occasion, especially if I get that …”oh that’s fishy” feeling when I am done.
In the end it does not matter. For the sake of the resource maybe catching as many fish as possible, as fast as possible is not something the majority of us should strive for, so in that sense, yeah, put some “soul” in your flies and fishing methods on occasion. Otherwise, fish how and what you feel most comfortable with.