There is a lot being said about productivity gains from GCed languages, but can you actually point me to any research showing these gains are real? My anecdota

There is a lot being said about productivity gains from GCed languages, but can you actually point me to any research showing these gains are real? My anecdotal, unscientific experience shows that GC is a double-edged sword that maybe makes writing simple programs slightly faster, at the expense of a much worse maintainability once the code base gets big. And non-memory resource management in GCed languages without RAII is a really huge PITA that kills all productivity gains. GC allowed memory safety until Rust happened, and that was a big gain, but now that point is moot.