The number 7 is seen as lucky in slots and pop culture because it often appears...

https://felixscoolop-eds.lumenforgex.com/posts/where-did-the-lucky-7-idea-come-from

The number 7 is seen as lucky in slots and pop culture because it often appears as the winning 777 combo on classic reels. It also connects to everyday life with things like the seven-day week, making it a familiar symbol of good fortune and balance