It’s the oldest and the greatest cosmic question of all: is there anybody out there?
It actually makes a lot of assumptions. Indeed, way too many assumptions for some that doubt its generous conclusions.
A key assumption is that it takes around five billion years for intelligent life to form on other planets, as it does on Earth, but that life is probable. That’s a big assumption, for sure. Another is that a technological civilization will last at least 100 years—as ours has, thus far. After all, it took 4.5 billion years of evolution before a technological civilization arose on Earth, and was capable of communicating.