Originally Posted by d-klumpp

Yes, several times, and here's just one example of potential benefit:

I was in a favorite shop that sells high-end bikes, including Seven and Parlee, for some new road cleats. The fitter asked why my saddle was set with the nose high, something I didn't intend nor noticed. He dropped the nose, pretty much imperceptibly to my eye. Strikingly though, on my next rides I noticed suddenly I'd gained 1.5-2.0 mph simply from his infinitesimal nosing down of my saddle. So that was an immediate and obvious performance gain from something simple. Meanwhile, there is no way to quantify the injuries possibly saved from prior fittings.

Cycling is like golf: some can do well with poor fit and form, but most benefit and even excel with a good fitting and good form. And it's hard to have good form without a good fit.