Larry is mostly reclusive from what I've read.
Sergey is working on bringing back blimp travel with his Lighter than Air (LTA) company: https://www.ltaresearch.com/
Business when you have unlimited money to your name to deploy is very different than when you are starting out.
For any self respecting man the process of doing press is a pain in the back. You see it in every domain ranging from sports to music to movies.
Ranging from Aaron Judge to Wayne Gretsky they will all tell you the same, the absolute hatred for interviews and doing press of any kind, but they are employees and the front office of their Franchise is forcing them to do so.
Once you are a billionaire those dynamics don't apply anymore, you don't have to convince bankers or venture funds or investors or the public anymore. It's a one man show and the only goal is to keep morale high among employees.