is there a benchmark that you are aware of that takes a cgi program and pits it against modern frameworks like node.js express , hono etc? just to get a feel of how many requests will be handled at scale
No, though there are many articles proving X is faster than Y along with articles proving the opposite.
The process overhead is likely to hurt CGI though, which is why FastCGI was developed. As covered elsewhere in the thread, having a fast front end with effective comms to a well-written backend seems a reasonably sweet spot.