Not the person you asked but I'm in exactly the same boat: coding since decades and had never heard of Deno (but I have "of course" at least heard of node.js and React and Angular and ...), have been mainly coding C++ and OpenCL/CUDA.
Deno is one of those things that makes it to the front page regularly (I’ve seen it here at least once every two months since it’s release) but if you aren’t on here every day or only started frequenting here recently I could easily see it being missed