I believe that rendering has entered an era similar to what audio synthesis encountered after sampling synths became pre-eminent - you can do more-or-less anyth

I believe that rendering has entered an era similar to what audio synthesis encountered after sampling synths became pre-eminent - you can do more-or-less anything given enough time, so the main focus of R&D turns towards providing better access, which in synthesis usually means presets. Rather than develop a custom program from scratch, it's more common to have a source library and then modify that into final material.