Personally i feel for the guy, imagine the whole world insisting you only work on the project you started back in 1991.
Honestly, the amount of writing doesn't even seem that useful of a metric. Stephen king only wrote ~3x more than George, and about 6x more than someone like Nabakov (1.5 to 2 million words across two languages). The real takeaway IMO is to just write regardless of the technology you use
And while not a novelist, Tarantino famously writes his screenplays all by hand as well.
Some notable examples I remember include J. R. R. Tolkien, Patrick O'Brian (who wrote all 21 books in the Aubrey-Maturin series by hand, and claimed at one point to write with "ink and quill"), Nabokov, Joyce Carol Oates, Ursula LeGuin, and Truman Capote.