I have been concerned about this for a while. I was one of the youngest people engaged in IETF when I started 25 years ago and if you set aside the grad students who participate while they are doing their thesis, I am still one of the younger participants.
If you look at average age, it is misleading because the younger folk don't tend to stick around. And that is probably due in large part to the dynamics of our industry which has an even bigger demographic issue that will probably not be acknowledged until the growth suddenly halts as Moore's law is repealed and all the youngsters go into biotechnology.
I do have a recruitment plan. I see a vast untapped desire for an open end-to-end secure federated
messaging service with Data at Rest security. There are proprietary schemes in that space (Signal, Telegram, AIP) but they are all limited in scope because they don't support open services and so it is impossible for two enterprises to connect unless they choose a single supplier.
There is a community that is very interested in deploying this technology to secure the communications infrastructures of political campaigns and I have begun making contacts in that regard. Some of you will remember I used the same strategy to promote the Web over rival network hypertext schemes in the early 90s.
So here is the curious thing, each one of the groups contacted so far has had the same response: This is something we should do but we should make our rivals aware of it as well because the end goal here is protecting the democratic process, not just winning an election.