Kay and his collaborators shipped Smalltalk, which was pretty widely used at one time, and which was also highly influential on Objective-C, the language of choice for OS X/macOS and iOS from 1996 to the introduction of Swift in 2014 (many devs are still using Objective-C).
That is fair, but why has he not shipped anything else? He's been content to sit back on his laurels for the past 40 years and make broad statements about OOP and the future of programming. Clearly Smalltalk was not the pinnacle of software development.
Like I said earlier, you probably haven't looked at Alan Kay's work in depth.
What did he do after Smalltalk? If it seems like nothing, it may be because you weren't the target demographics. He cared about teaching children computational thinking. Squeak, Etoys, etc. https://en.wikipedia.org/wiki/Alan_Kay#Subsequent_work
