I think Ready to Die was the album to open up that lane. That album and Nas losing to Big at the Source Awards is what led to IWW being made the way it was
The difference is Ready To Die wasn't flossy with the commercial gloss or polish that IWW had. With It Was Written, Nas managed to balanced the Trackmasters flair for turning '80's Pop loops into commercial smashes with production from Havoc and Premier. He still kept the storytelling vivid and the lyricism sharp, but he was more laid back and took the risk to sing, which Biggie also did on Life After Death after dabbling with it a little bit on Ready To Die (his attempt at singing "What's Love Got To Do" during one of the verses).