Almost everyone will just use their search engine to find this page: https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
What can you do to serve the licence to those who can't or won't do that (for whatever reason)? I think it is hard to find something more universally accessible to serve that edge case.
You describe your story of how sending a letter went to you, and I admit it sounds like a bit of a pain. But you managed to do it. And by the sound of it you were totally novice at it. (didn't even bring your own pen!) Someone can do the same thing you did anywhere from Nairobi, McMurdo, Pyongyang, or Vigánpetend.
It is not "universally accessible" in the "easy and comfortable" sense. It is "universally accessible" in the "almost anywhere where humans live you can access this service" sense.