Bingo is a meme that has been used to represent many different things, such as being an idiom, a distraction tactic, or even a way to show support. However, it is most commonly known as the Farmer meme. Bingo is often used as a way to mock people who are engaged in repetitive or mindless activities, such as playing video games or watching TV. The Farmer meme is based on the joke that bingo is a game where you randomly draw numbers and hope to get a combination that matches the ones already played.
The joke is that this is a very similar strategy to farming, which is usually done by hand. By using bingo as an analogy for farming, the joke makes it clear that the person playing bingo is not taking their game seriously.