How often do Japanese people actually say “いただきます!”?

When I was in Japan as an exchange student, I realized that, despite learning that people say this phrase before they eat, that I very rarely ever heard it being used.

Is this because it’s less modern? Are children taught to do it, and then they grow out of it? Does it depend on the region? Would it be considered childish or weeaboo-ish if I said it?