I hope tis makes for an interesting discussion...

Very frequently when discussing ways of doing things it is said in some way or another...." well the fish don't seem to care".

I will submit that maybe they do...e.g.

On a day when they didn't bite at all if you had used the best technique, fly, whatever...maybe you would have caught some fish...

Or say you caught fish but if you had done something different maybe you would have caught say 10% more...

or maybe you would have fooled an older larger fish

Just a little example that we have been talking about...suppose you knowingly use material on a woolly bugger that doesn't give as much motion as another material that you could have used....sure it will catch fish but who is to say you wouldn't have done better

And yes I know it isn't always about doing better but why not do the best you can? ...at least without being obsessive