You can refer to his bio on Wikipedia [1], but the question itself seems a bit off, as it assumes that someone needs to have accomplished something specific to be worth listening to. While I’m not talking about Kurzweil in particular, the truth is, you don’t necessarily need a list of achievements to say something valid or correct. For instance, Isaac Newton made groundbreaking discoveries, yet also devoted significant time to alchemy [2].
The thing is I know of Kurtzweil from the time he worked on synthesizers. His AI stuff and singularity stuff always felt like gimmicks to me even back then.
[1] https://en.wikipedia.org/wiki/Ray_Kurzweil
[2] https://en.wikipedia.org/wiki/Isaac_Newton#Alchemy”