This seems like an awfully - and very academic - strange question. "Have there been controlled studies to see if this thing that millions of developers have personally experienced value from actually has value?"

No, I rather suspect not. What's more curious is the implied suggestion that VC has no value if it has not been empirically proven through formal scientific study.

I also suspect that you will find no papers on the effectiveness of building a house using a hammer and nails and making it up as you go versus using a nailgun and blueprints, but as man has known since he first discovered fire, better tools pretty much always mean faster and higher-quality results.