That's true for me, too. But I can communicate with those people via other means and have found no downside to doing so. I've been Facebook- free for years now.
But they don't need convincing for us to leave Facebook. My friends who have Facebook also have text, email, phone, and sometimes WhatsApp, Signal, and/or Telegram. AFAIK I haven't ever convinced anyone to leave Facebook, but that hasn't been a barrier to me leaving Facebook at all.